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ISBN 978-951-42-9666-6 (Paperback)ISBN 978-951-42-9667-3 (PDF)ISSN 0355-3221 (Print)ISSN 1796-2234 (Online)

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Marjo Tourula

OULU 2011

D 1137

Marjo Tourula

THE CHILDCARE PRACTICE OF CHILDREN’S DAYTIME SLEEPING OUTDOORSIN THE CONTEXT OF NORTHERN FINNISH WINTER

UNIVERSITY OF OULU,FACULTY OF MEDICINE,INSTITUTE OF HEALTH SCIENCES, NURSING SCIENCE,INSTITUTE OF BIOMEDICINE, DEPARTMENT OF PHYSIOLOGY;FINNISH INSTITUTE OF OCCUPATIONAL HEALTH, OULU;NORTHERN OSTROBOTHNIA HOSPITAL DISTRICT;KYUSHU UNIVERSITY, FACULTY OF DESIGN, DEPARTMENT OF HUMAN SCIENCE

A C T A U N I V E R S I T A T I S O U L U E N S I SD M e d i c a 1 1 3 7

MARJO TOURULA

THE CHILDCARE PRACTICE OF CHILDREN’S DAYTIME SLEEPING OUTDOORS IN THE CONTEXT OF NORTHERN FINNISH WINTER

Academic dissertation to be presented with the assent ofthe Faculty of Medicine of the University of Oulu forpublic defence in Auditorium 101 A of the Faculty ofMedicine (Aapistie 5 A), on 2 December 2011, at 12 noon

UNIVERSITY OF OULU, OULU 2011

Copyright © 2011Acta Univ. Oul. D 1137, 2011

Supervised byProferssor Arja IsolaProfessor Hannu RintamäkiProfessor Juhani Hassi

Reviewed byDocent Päivi KankkunenProfessor Randi Eidsmo Reinertsen

ISBN 978-951-42-9666-6 (Paperback)ISBN 978-951-42-9667-3 (PDF)

ISSN 0355-3221 (Printed)ISSN 1796-2234 (Online)

Cover DesignRaimo Ahonen

JUVENES PRINTTAMPERE 2011

Tourula, Marjo, The childcare practice of children’s daytime sleeping outdoors inthe context of Northern Finnish winterUniversity of Oulu, Faculty of Medicine, Institute of Health Sciences, Nursing Science; Instituteof Biomedicine, Department of Physiology, P.O. Box 5000, FI-90014 University of Oulu,Finland; Finnish Institute of Occupational Health, Oulu, Aapistie 1, FI-90220 Oulu, Finland;Northern Ostrobothnia Hospital District, P.O.Box 10, FI-90029 OYS, Finland; KyushuUniversity, Faculty of Design, Department of Human Science, 4-9-1 Shiobaru, Minami-ku,Fukuoka 815-8540, JapanActa Univ. Oul. D 1137, 2011Oulu, Finland

AbstractThe purpose of the study was to create a comprehensive view and add understanding about thechildcare practice of children sleeping outdoors in the context of Northern Finnish winter. Ageneral view of the topic was described, the thermal insulation of clothing of infants sleepingoutdoors in northern winter climate was evaluated and the relationships among thermalenvironment, infants’ skin temperatures and daytime outdoor sleep duration were described.

Mixed methods research design was used. A questionnaire was distributed to the parents(n=116) of children under 2 years of age in the city of Oulu. Skin temperatures of about three-month-old infants were recorded from seven skin sites throughout a daytime sleep outdoors (n=34)and indoors (n=33) in the families’ homes. The duration of the infant’s sleep was observed and airtemperature and velocity of the outdoor environment were recorded. Clothing data of infants werecollected and microclimate temperatures and humidity inside middle wear measured. Theinsulation of clothing ensembles was measured by using a baby-size thermal manikin. Therequired clothing insulation was estimated according to ISO 11079. Mothers (n=21) fromNorthern Finland were interviewed.

A fit can be found between family – cultural outdoor sleeping childcare practice – and NorthernFinnish winter environment, but also factors that decreased the fit existed. Winter environmentwas seen as an affordance for the child to sleep outdoors. Infants usually slept outdoors in thedaytime once a day in different kinds of environments, the best temperature being -5 °C. Outdoorsleeping was a self-evident and common culturally bound custom. Guidelines and encouragementwere given to mothers from different sources, and by sharing their own experiences, mothersparticipated in the cultural knowledge-building processes. The outdoor sleeping practice wascommonly accepted collective behavior. Many risk factors also existed, but when all securityperspectives were first taken into account it promoted family well-being by creating rhythm andstrengthening the fluency of everyday life. The optimal thermal insulation was difficult to adjustsystematically and both cooling and sweating existed. When ambient temperature decreased, thecooling rate of Tsk increased. Children slept longest outdoors when the cooling rate of Tsk wasminimal. The basic idea was that outdoor sleeping promoted children’s health.

A comprehensive view of the phenomenon was gathered into the evaluation model, which canbe utilized in nursing practice. The findings give detailed information that is utilized whenupdating guidelines. This study also creates ground for international comparative studies.

Keywords: child, child care, culture, mixed methods, Northern Finland, skintemperature, sleep, thermal insulation of clothing, winter

Tourula, Marjo, Lasten ulkona nukuttaminen talvella lastenhoitokäytäntönäpohjoissuomalaisessa kontekstissa Oulun yliopisto, Lääketieteellinen tiedekunta, Terveystieteiden laitos, Hoitotiede; Biolääke-tieteen laitos, Fysiologia, PL 5000, 90014 Oulun yliopisto; Työterveyslaitos, Oulu, Aapistie 1,90220 Oulu; Pohjois-Pohjanmaan sairaanhoitopiiri, PL 10, 90029 OYS; Kyushun yliopisto,Suunnittelun tiedekunta, Ihmistieeteet, 4-9-1 Shiobaru, Minami-ku, Fukuoka 815-8540, JapaniActa Univ. Oul. D 1137, 2011Oulu

TiivistelmäTutkimuksen tavoitteena oli muodostaa kokonaiskuva ja lisätä ymmärrystä lasten ulkona nukut-tamiskäytännöstä pohjoissuomalaisessa talvikontekstissa lasten ja perheiden hyvinvoinninlisäämiseksi. Tarkoituksena oli kuvata lasten ulkona nukuttamiskäytäntöä, ympäristön ja ihonlämpötilojen sekä unen pituuden yhteyttä ja arvioida vaatetuksen lämmöneristävyyttä.

Tutkimuksessa käytettiin mixed methods -lähestymistapaa monipuolisen kokonaiskuvantavoittamiseksi. Pilottikysely tehtiin alle 2-vuotiaiden lasten vanhemmille (n=116) Oulun alueel-la. Ihon lämpötiloja mitattiin seitsemästä eri kehon osasta noin kolmen kuukauden ikäisiltä lap-silta (n=34) heidän nukkuessaan kotona päiväuniaan sisällä ja ulkona Pohjois-Suomessa talvel-la. Unen pituutta havainnoitiin ja ympäristön lämpötilaa ja tuulen nopeutta mitattiin. Lasten tal-vivaatetuksesta kerättiin tietoa ja lämpötiloja mitattiin vaatetuksen eri kerroksista sekä kosteuttavälivaatetuksen alta. Vaatetuksen lämmöneristävyyksiä mitattiin lasten kokoa vastaavalla lämp-önukella. Vaadittava lämmöneristävyys arvioitiin ISO 11079 – standardin mukaisesti. Pohjois-suomalaisia lapsiperheiden äitejä (n=21) haastateltiin kulttuurisen tiedon esille tuomiseksi.

Yhteensopivuus perheen, kulttuurisen ulkona nukuttamiskäytännön ja pohjoisen talviympär-istön välillä voidaan saavuttaa, mutta toisaalta myös tasapainoa vähentäviä tekijöitä löytyi. Tal-viympäristö nähtiin tarjoumana lapsen rauhalliselle nukkumiselle sen puhtaan ja raikkaan ilmanja luonnon sekä hiljaisuuden ja rauhallisuuden takia. Talvinen sää vaihteli auringon paisteestakovaan lumipyryyn ja lämpötila muutamista lämpöasteista lähes kolmenkymmenen asteen pak-kaseen lasten nukkuessa vaunuissaan. Paras lämpötila ulkona nukkumiselle oli -5 °C. Ulkonanukuttamista pidettiin itsestään selvänä kulttuurisena tapana. Äidit saivat ohjeita ja kannustustalasten ulkona nukuttamiseen eri lähteistä. Vertailemalla ja jakamalla kokemuksiaan he osallistui-vat myös itse kulttuurisen tiedon rakenteluun. Lasten ulkona nukuttaminen talvella osoittautuiyleisesti hyväksytyksi kollektiiviseksi käyttäytymiseksi, joka toisinaan aiheutti paineita äideille.Lapsen ulkona nukkumiseen liittyi monia riskitekijöitä, mutta kaikki turvallisuusnäkökohdatensin huomioon ottamalla se edisti perheen hyvinvointia luomalla säännöllistä rytmiä ja vahvis-tamalla arjen sujuvuutta. Optimaalisen vaatetuksen lämmöneristävyyden löytäminen systemaat-tisesti eri lämpötiloissa oli vaikeaa; sekä jäähtymistä että hikoilua esiintyi. Ympäristön lämpöti-lan laskiessa keskimääräisen ihon lämpötilan jäähtymisnopeus lisääntyi. Lapset nukkuivat ulko-na pisimpään silloin, kun ihon lämpötilan jäähtyminen oli hitainta. Ensisijaisesti ulkona nukku-misen ajateltiin edistävän lapsen terveyttä.

Lasten ulkona nukuttamisen arviointimallia voidaan hyödyntää käytännössä ohjauksen yhte-ydessä ja tutkimuksen tuottamaa yksityiskohtaista tietoa ohjeistusten päivittämisessä. Tutkimusantaa lähtökohtia kansainväliselle vertailevalle tutkimukselle.

Asiasanat: ihon lämpötila, kulttuuri, lapsi, lastenhoito, mixed methods -lähestymistapa,Pohjois-Suomi, talvi, uni, vaatetuksen lämmöneristävyys

To Tuomo, Eetu, Olli, and Aaro

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9

Acknowledgements

This study was carried in co-operation with the Institute of Health Sciences and

the Institute of Biomedicine at the University of Oulu as well as Finnish Institute

of Occupational Health, Oulu, Northern Ostrobothnia Hospital District and the

Department of Human Science at the Kyushu University.

Most importantly, I would like to thank all families for your participation. I

appreciate your interest in my study and your contribution to it making this thesis

possible. I want to thank those public health nurses and other persons who helped

me to contact the study families.

My warmest appreciation and the most grateful acknowledgements go to my

supervisors Professor Arja Isola, Professor Hannu Rintamäki and Emeritus

Professor Juhani Hassi. I want to express my deepest gratitude to Arja for your

encouragement, support and advice during my academic studies, especially

during these five years when I have been privileged to work as a doctoral

candidate at the Institute of Health Sciences. I am very grateful for your

enthusiasm when I presented the idea of my research, your trust and that you have

encouraged me to continue until the doctoral thesis. I want to express my special

gratitude to Hannu for inspiring me in the field of thermophysiology. I am very

grateful to you for helpful discussions and valuable support. I highly appreciate

that you always gave me time when I needed to reflect many kinds of issues. I

want to thank Juhani for introducing me to the field of cold research. You had a

significant role in encouraging me to do research in this field.

I would like to express my grateful acknowledgements to The Vice-President,

Professor, Yutaka Tochihara, at the Kyushu University. I highly appreciate that

you gave me the possibility to do the clothing insulation measurements at the

Faculty of Design. I am grateful to Takako Fukazawa, PhD, for your guidance,

valuable comments and patience when introducing me to the field of clothing

insulation measurements. I highly appreciate our cooperation. I wish to express

my gratitude to Koji Tabata as well as the students and the staff at the Research

center for human environmental adaptation for your help with thermal manikin

measurements. My family and I want to express our gratitude to Hitoshi

Wakabayashi, PhD, for sharing with us many unforgettable moments in Japan and

in Finland. I have been privileged to meet all of you.

I want to express my gratitude to Professor Leena Paasivaara and Docent

Sirkka Rissanen, members of the follow-up group, for your valuable comments. I

am grateful to the official referees of the dissertation, Professor Randi Eidsmo

10

Reinertsen and Docent Päivi Kankkunen, for your careful review and valuable

advice to improve this thesis.

I want to express gratitude to Risto Bloigu, MSc, for your statistical guidance,

Anna Vuolteenaho, MSc, for revising the language of my manuscripts and this

thesis, Pertti Tuhkanen, specialized occupational hygienist, for helping with the

measurement of relative humidity, Raija Heino, information specialist, for helping

me in literature searches and Aino-Maria Vuoti, senior in visual communication,

for graphic designing of figure 5.

I am grateful to the staff at the Institute of health sciences, department of

nursing science and health administration for all the support I got during these

years. Working with you and our fruitful discussions have been important to me. I

want to thank docent Tarja Pölkki for inspiring discussions about research among

children.

I warmly thank my fellow students and friends especially Hanna, Maire,

Eeva-Leena, Merja, Outi, Leena, Ulla, Pirjo and Jaana for our conversations that

have been very helpful for me, your support and sharing experiences with me. I

also express my gratitude to all doctoral candidates at the Finnish Post-Graduate

School in Nursing Science.

I would like to thank my friends, Helinä and Minna, for offering refreshing

company and support.

I want to thank my parents, Anni and Paavo, for your encouragement, support

and help throughout my life. Moreover, I want to thank my siblings, Kirsi, Satu,

Marko and Heli for everything. You and your families will always have a special

place in my life. I also thank Leena, Pentti, Tapio, Ilkka, Outi and your families

for your support.

My dearest gratitude is expressed to my husband, Tuomo. We have shared our

lives; thank you for your love and patience. Our sons, Eetu, Olli and Aaro are the

most important persons in my life. Thank you for richening my life in so many

ways.

This study was financially supported by the Finnish Post-Graduate School in

Nursing Science, the Graduate School of Circumpolar Wellbeing, Health and

Adaptation, Northern Ostrobothnia Hospital District and Health Science

Academic Leaders and Experts.

Oulu, October 2011 Marjo Tourula

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List of abbreviations and definitions

BAT brown adipose tissue

°C Celsius

CI confidence interval

CIS cold injury syndrome

CLO thermal insulation of clothing, 0.155 m2 °C/W

CV coefficient of variation

Icl basic thermal insulation, m2 · K · W–1

Icle effective clothing insulation, m2 · K · W–1

IREQ required clothing insulation, m2 · K · W–1

ISO International Organization for Standardization

It total thermal insulation, m2 · K · W–1

M metabolic rate (W/m2)

REM rapid eye movement sleep

RH% relative humidity

rs Spearman’s rank correlation coefficient

SD standard deviation

SIDS sudden infant death syndrome

Tsk mean skin temperature (°C)

VO2 oxygen consumption

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13

List of original publications

This thesis is based on the following articles, which are referred to in the text by

their Roman numerals:

I Tourula M, Isola A & Hassi J (2008) Children sleeping outdoors in winter: Parents’ experiences of a culturally bound childcare practice. International Journal of Circumpolar Health 67(2–3): 269–278.

II Tourula M, Isola A, Hassi J, Bloigu R & Rintamäki H (2010) Infants sleeping outdoors in a northern winter climate: skin temperature and duration of sleep. Acta Paediatrica 99(9): 1411–1417.

III Tourula M, Fukazawa T, Isola A, Hassi J, Tochihara Y & Rintamäki H (2011) Evaluation of the thermal insulation of clothing of infants sleeping outdoors in Northern winter. European Journal of Applied Physiology 111(4): 633–640.

IV Tourula M, Pölkki T & Isola A (2011) The cultural meaning of children sleeping outdoors in Finnish winter: A qualitative study from the viewpoint of mothers. Manuscript.

In addition, some unpublished data are presented in the thesis.

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15

Table of contents

Abstract

Tiivistelmä

Acknowledgements 9 

List of abbreviations and definitions 11 

List of original publications 13 

Table of contents 15 

1  Introduction 17 

2  Review of the literature 19 

2.1  The concept of environment .................................................................... 19 

2.2  Winter environment in Northern Finland ................................................ 21 

2.3  Families’ cultural childcare ..................................................................... 22 

2.4  Cultural clothing practice and thermal resistance ................................... 25 

2.5  The well-being of children in the north ................................................... 27 

2.6  Sleep of children ..................................................................................... 29 

2.7  Thermal environment of children ............................................................ 34 

2.7.1  Thermal balance and thermoregulation ........................................ 34 

2.7.2  Interaction between sleep and thermoregulation .......................... 37 

2.7.3  Symptoms of thermal stress .......................................................... 39 

2.8  Summary of the literature........................................................................ 40 

3  Aims and hypotheses of the study 43 

4  Methodology 45 

4.1  Mixed methods research design .............................................................. 45 

4.2  Subjects and settings ............................................................................... 48 

4.3  Procedures, data collection and analysis ................................................. 49 

4.3.1  Children sleeping outdoors in winter from the viewpoint

of parents ...................................................................................... 49 

4.3.2  Observation and physiological measurement of infants ............... 51 

4.3.3  Microclimate and clothing insulation measurements ................... 54 

4.4  Ethical considerations ............................................................................. 58 

5  Results 61 

5.1  Winter environment in Northern Finland ................................................ 63 

5.2  Cultural knowledge-building .................................................................. 64 

5.3  Family well-being ................................................................................... 66 

5.4  Winter clothing of outdoor sleeping children .......................................... 69 

5.5  Well-being of the children ....................................................................... 74 

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5.5.1  Children’s sleep ............................................................................ 74 

5.5.2  Children’s skin temperatures ........................................................ 77 

6  Discussion 81 

6.1  Validity and reliability of the quantitative studies ................................... 81 

6.2  Trustworthiness of the qualitative study .................................................. 85 

6.3  Discussion of the results .......................................................................... 86 

6.3.1  Winter environment in Northern Finland ..................................... 86 

6.3.2  Cultural knowledge-building ........................................................ 87 

6.3.3  Family well-being ......................................................................... 89 

6.3.4  Winter clothing of outdoor sleeping children ............................... 91 

6.3.5  Well-being of the children ............................................................ 94 

6.4  Summary of the findings and conclusions .............................................. 97 

6.5  Implementation and suggestions for future research ............................... 98 

References 101 

Appendices 121 

Original publications 129 

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1 Introduction

”All people who coat their children with clay or butter, wrap them in buffalo hide

or tapa or silk, swaddle them or fasten them on cradle boards will give as the

primary reason for so doing their desire to protect the child” (Mead 1954: 400).

Cultural communities provide their own developmental pathways for their

children within a specific cultural context, and these cultural pathways are made

up of everyday routines of life (Weisner 2002). The goal of improving children’s

well-being is a common point of view, but consensus as to what is the best

sleeping arrangement for children cannot be found despite many decades of

research (Giannotti & Cortesi 2009).

Sleep problems in children are a major issue of concern to parents (Sadeh &

Anders 1993, Morrell 1999, Thunström 1999, Lam et al. 2003, Wake et al. 2006,

Bayer et al. 2007, Martin et al. 2007), and they experience low efficacy related to

infant’s daily rhythm and sleep (Salonen et al. 2008). Infants’ sleep problems

have more extensive effects on family well-being.

In Finland, the first guidelines pointing out how important and good it is for

children’s health to have them sleep outdoors in the winter came out in the 1920s

(Ylppö 1921); today it is a culturally bound custom. However, infants’ greater risk

for hypothermia due to their physiological characteristics (Pocock et al. 1999) as

well as the geographical location of Finland between the 60th and 70th northern

parallels of latitude and its cold winters (Finnish Meteorological Institute 2011)

highlight the safety aspects of this childcare practice.

Sleep is biological behavior of the child, as well as being strongly affected by

cultural values and beliefs (Jenni & O’Connor 2005). Cultural differences of

childcare practices dealing with children’s sleep and studies comparing cultures

can be found, but according to the review of Jenni & O’Connor (2005), scientific

literature is scant, widely scattered, and narrowly focused. Hardly any of the

previous studies have even mentioned children sleeping outdoors in the winter. To

our knowledge, this is the first study to focus on children’s daytime sleeping

outdoors, although it is a common childcare practice in the Nordic countries

(Reima group 2009). In Finland, 60,980 children were born in 2010, and there are

30,1621 children at the age of 0–4 years (Tilastokeskus 2011), which means that

the outdoor sleeping practice concerns many children and families in Finland. Just

like McKenna et al. (2007) considered in their article how several generations

have been influenced to treat their babies in a certain way and why it came to be

considered “normal”, in this study answers are sought to the meaning of children

18

sleeping outdoors in the winter. Without an understanding of sleep characteristics

in different cultures, it is difficult to provide guidelines and counseling on sleep

and what is normal or expected (Mindell et al. 2010b).

Sleep studies most often focus on nighttime sleep instead of assessing the

roles of daytime sleep (Schwichtenberg et al. 2011). The clothing and wrapping

of infants and thermal environment have been studied, as overheating is

associated with SIDS (sudden infant death syndrome) (Eiser et al. 1985, Bacon et

al. 1991, Wigfield et al. 1993, Watson et al. 1998, Vennemann et al. 2009).

Studies have also addressed newborn babies’ thermal environment in incubators

(Telliez et al. 1998, Bach et al. 2000ab, Bach et al. 2001, Telliez et al. 2004) as

well as using baby-size manikins (Elabbassi et al. 2001, Elabbassi et al. 2002,

Elabbassi et al. 2004) and infants’ thermal environment in the home setting in

New Zealand (Nelson & Taylor 1989, Baddock et al. 2004) and England (Eiser et

al. 1985, Nicoll & Davies 1986, Wailoo et al. 1989ab, Bacon et al. 1991, Wigfield

et al. 1993) during the day (Anderson et al. 1990) and night (Lodemore et al.

1992, Wigfield et al. 1993). McCullough et al. (2009) have developed a

temperature ratings model for children’s cold weather clothing from the age of

four years for the activity level of walking, but no studies were found about

infants’ thermal environment and winter clothing used outdoors during daytime

sleep in a northern country.

The purpose of this study is to create a comprehensive view and add

understanding about the childcare practice of children sleeping outdoors in the

context of Northern Finnish winter for enhancing the well-being of children and

families. A general view of the topic is described and created, the thermal

insulation of clothing of infants sleeping outdoors in the northern winter climate

is evaluated and the relationships between thermal environment, infants’ skin

temperatures and daytime outdoor sleep duration are described.

The paradigm of nursing science is defined through its essential concepts:

human being, health, nursing and environment (Kankkunen & Vehviläinen-

Julkunen 2010), all of which are concerned in this study. This doctoral thesis

belongs to the field of applied clinical nursing research, which begins with

practice-related questions (Polit & Beck 2010). Public health nurses have

counselled families about children's outdoor sleeping since the 20th century. This

study provides a basis for and viewpoints on this counseling.

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2 Review of the literature

2.1 The concept of environment

Environment is a complex entity consisting of spatial, temporal and qualitative

characteristics. When the environment is viewed spatially, concentric circles can

be defined to be around the person in the center where some elements of the

environments have a direct impact upon the person’s life while some only

influence it in minor ways. Viewed temporally, the environment includes the

duration and manner of presence; elements exist continuously, intermittently or

fleetingly as well as regularly or randomly. Environment can be classified

qualitatively into physical, social and symbolic environment. The main concept in

the physical environment is ecosystem, which can be defined as a system of

interactions among the various human groups themselves and with the physical

and chemical components of the environment where the basic process is energy

transfer between and among elements of the environment. Physical environment

is composed of biotic elements ranging from viruses to human beings, and abiotic

elements, i.e. artifacts starting with clothing as the most proximal elements and

extending to satellites orbiting the earth. Individuals and groups with whom a

person interacts constitute the social environment, whereas symbolic environment

consists of ideational elements (ideas, values, beliefs, history, and knowledge),

normative elements (rules, laws, expectations, and constraints) and institutional

elements (roles, organizations, institutions, society, and culture). (Kim 2000.)

According to Bronfenbrenner (1977, 1979), children’s development should be

studied by taking account of the multilevel social, material and cultural context.

The most proximal first level is microsystem level, consisting of the physical,

social and symbolic characteristics of the environment determining the conditions

either promoting or inhibiting a child’s development. Mesosystems are collections

of a child’s daily environments’ microsystems and the synergetic effects of the

various components. Exosystems, such as the health care system, are not

necessarily a part of an individual’s system, but affect peoples’ lives nevertheless.

Macrosystem is the cultural level affecting the micro-, meso- and exosystems.

Background, age, culture, and conditions of life affect the meanings that we

give to the environment (Lindheim & Syme 1983), and for that reason everyone

experiences the environment in their own way, changing the objective

environment into subjective life space (Lewin 1917, cited by Bronfenbrenner

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1977). Attachments are formed to places that fulfill emotional needs and make it

possible to develop and maintain people’s identities (Kaiser & Fuhrer 1996).

Favorite places affect psychological well-being and eventually health (Korpela

2002). Korpela (1989) has described that physical environments can be used to

regulate pleasure/pain and self-experience, and those regulation processes that

produce experiences and cognitions partly form a place identity. Proshansky et al.

(1983: 59) have described place identity as follows:

“These cognitions represent memories, ideas, feelings, attitudes, values,

preferences, meanings, and conceptions of behavior and experience which

relate to the variety and complexity of physical settings that define the day-

to-day existence of every human being. At the core of such physical

environment-related cognitions is the ‘environmental past’ of the person; a

past consisting of places, spaces, and their properties which have served

instrumentally in the satisfaction of the person’s biological, psychological,

social, and cultural needs.”

According to the study of Barker (1987) daily activities seemed to consist of

operational cycles, episodes with varying durations, most of which were

determined by environment and behavior setting. Episodes are series of

meaningful, goal-directed actions (Hoogsteder et al. 1998). According to

Leininger (1997), environmental context includes events with meanings and

interpretations in physical, ecological, sociopolitical and cultural settings.

Several child-rearing variables have been shown to have associations with the

presence of environmental affordances and demands, which play an important

role in influencing maternal behavior by acting as environmental cues for place-

related behavior (Miller et al. 1998). In the field of environmental psychology,

place rules for behavior are seen in situations when human actions fit into the

place in which they occur (Canter 1992). The term affordance can be defined as

what the environment offers to persons for actions to be undertaken (Gibson

1986). Affordances are prerequisite for action (Greeno 1994). There are potential

affordances and actualized affordances consisting of perceived, utilized and

shaped affordances (Heft 1989, Kyttä 2003). Related to the perception and

actualization of affordances are a person’s skills, practice, strength, goals and

intentions (Costall 1995). Affordances can be seen in different ways in different

cultures due to socialization (Reed 1996, Kyttä 2003). Each person may also see

uniquely apparent emotional coloring of affordances (Kyttä 2003) and due to

21

individuals’ different perceptions, affordances can be seen as positive or negative,

as benefits or injuries, as safeties or dangers (Gibson 1986).

A healthy environment provides a range of opportunities for its inhabitants to

shape the conditions that affect their lives (Lindheim & Syme 1983), safety,

opportunities for social integration, and the ability to predict and/or control

aspects of the environment, whereas unhealthy environments are those that

threaten safety and undermine the creation of social ties, and that are conflictual,

abusive, or violent (Taylor & Repetti 1997). Circumstances of the physical and

emotional environment impact children’s health and set the groundwork for future

vulnerabilities and resiliencies (Reading & Wien 2009). A quiet, safe living

environment has been described to increase families’ sense of well-being (Åstedt-

Kurki et al. 1999).

The term context has been defined as the contents of the immediate situation

but also broader contents of the neighborhood, community, and culture

(Bronfenbrenner 1979). In this study the term context means the surroundings

from the immediate physical level of infant’s skin and clothing to the more distant

levels of social and cultural surroundings and northern winter environment.

2.2 Winter environment in Northern Finland

The northern region can be defined to encompass the areas in the northern parts of

the United States, Canada, Denmark, Iceland, Norway, Sweden, Finland and the

Russian Federation (Young 2008). In this study, when the north is viewed

worldwide, areas located above 60°N latitude and thus the whole Finland is

defined as north, whereas when the north is viewed nationally, only the areas of

the Kainuu region, Northern Ostrobothnia and Lapland are located in the north.

The Finland’s geographical position between the 60th and 70th northern

parallels of the latitude in the Eurasian continent's coastal zone causes

characteristics of both a maritime and a continental climate, depending on the

direction of air flow. A quarter of the surface area of Finland lies to the north of

the Arctic Circle and is situated on the same latitudes as Alaska, the southern part

of Greenland and Siberia, but the mean temperature is several degrees higher due

to the Baltic Sea, inland waters and airflows from the Atlantic, which are warmed

by the Gulf Stream. However, the Asian continental climate can be seen in

Finland as severe cold in winter. The lowest temperature in Finland, recorded in

1999, is −51.5°C. Weather types can change rapidly in winter and snow- and

rainfalls are typical. (Finnish Meteorological Institute 2011.) Windy weather

22

increases the cooling effect on the skin that can be expressed as wind chill

temperature (ISO 11079 2007).

Winter can be defined to be the longest season in Finland, lasting from 100 to

200 days, as it begins when the mean temperature remains below 0°C. Permanent

snow covers open grounds about two weeks after winter begins and the lakes

freeze over in late November and early December. (Finnish Meteorological

Institute 2011.)

The "polar night" is the period lasting for 51 days, when the sun does not rise

above the horizon at all north of the Arctic Circle. The day is also short in

southern Finland, lasting only about 6 hours. (Finnish Meteorological Institute

2011.)

Climate can be defined as long-term average weather, and observations have

been made to indicate that the climate has changed. Earth’s average temperature

has increased, and the probabilities of certain types of weather phenomena have

become more frequent and intense, such as heat waves and heavy downpours,

while others have become less frequent and intense, such as extreme cold events.

(Le Treut et al. 2007.)

2.3 Families’ cultural childcare

Culture can be defined in a variety of ways (Kao et al. 2004), such as sets of

beliefs, norms, and expectations, but it is also more complex, the entire

nonbiological inheritance of human beings, everything that is socially constructed

and learned (Hufford 1990, cited by Jenni & O’Connor 2005). The definition of

culture is ambiguous, being sometimes too narrow, omitting salient viewpoints, or

too general, so that when it loses its real meaning (Kao et al. 2004). According to

Shore (1996: 44), culture can be defined as “an extensive and heterogeneous

collection of “models”, models that exist both as public artefacts “in the world”

and as cognitive constructs “in the mind” of members of a community”. Culture

can be seen in a static perspective as a system of rules that can be measured and

predicted. In a dynamic perspective culture is seen with no concrete reality

existing in a person’s mind as a cognitive system with shared symbols and system

of meanings. (Kao et al. 2004.)

Culture is dynamic and adaptive in response to the environment (Lenburg et

al. 1995), when people with cultural backgrounds and experiences actively

interact with their environments (Kao et al. 2004). Culture can be seen

comprehensively as a way of life over time and in different geographic locations

23

(Leininger 2006). Cultural practices are often taken for granted by its members,

but may seem strange and not understandable to persons outside the culture

(Connolly et al. 2006).

The idea of locally rational action can be found in ecocultural theory (Shore

1996). Local situations are comprised of everyday routines and activities where

connected, schematized and shared cultural knowledge is used to adapt and make

complex decisions to survive in local communities. It is possible to enter families’

cultural pathways by interviewing and observing their daily routines. (Weisner

2002.) Chess and Thomas (1984: 21) defined the interaction with environmental

demands by using the concept of “goodness of fit”, which can be attained “when

the organism’s capacities, motivations and style of behaving and the demands and

the expectations of the environment are in accord”. Environmental situations may

have a positive effect on well-being by enhancing fit between a person’s goals,

activities, and surroundings or negative effects by reducing the level of person-

environment fit (Wicker 1972).

In a study of Winch et al. (2005) where local knowledge from Bangladesh

related to newborn period was studied, newborns were seen as vulnerable to cold

and cold was thought to cause many problems. However, some of their practices,

such as keeping the infant on a mat on the floor could increase the risk of

hypothermia. (Winch et al. 2005.) At the same time, Swedish mothers considered

the outdoors an appropriate and desired environment for their infants and

achieved good health for infants by daily walks, provided healthy doses of fresh

air and toughened the child to the cold climate. This was in contrast to Italian and

American mothers, who prevented exposure to cold. (Welles-Nyström et al. 1994.)

Culture in different contexts is influenced by how mothers see affordances, and

these affordances and demands create cues for appropriate place-related behavior

(Miller et al. 1998).

History is part of our shared cultural knowledge. Childcare practices and the

meanings of these practices have varied in different eras. At the time of Greeks

and Romans, for example, it was thought necessary for infants to be exposed to

cold and heat and to harden the baby’s skin by salting it with soda ash (Lipton et

al. 1965). Spartan-like hardening after birth by bathing newborns in very cold

water disappeared in the second quarter of the 19th century (Korones 2004). Until

in 1958, lower environmental temperature was found to associate with higher

mortality of infants (Silverman et al. 1958). Infants have slept tightly swaddled

and in different kinds of beds; infant baskets and cradleboards, such as woolen

canoe-like cradles, have been used, and infants have been carried on parents’

24

backs by the Sami people in Lapland while tending reindeer herds. (Lipton et al.

1965.) However, little attention has been paid to the historical point of view in

terms of sleeping arrangements (Stearns et al. 1996).

The interest in child development and the significance of children’s sleep

started to increase internationally in the late 19th century, focusing first on

physical health issues and material arrangements. For example, popular health

columns in women’s magazines discussed how much covering should be use to

avoiding overheating and underprotection of the child. Parents were told to avoid

getting children’s feet cold, because this was associated with dangerous

conditions such as fatal sore throat. Children were thought to need regularity and

rituals as well as appropriate physical arrangements: proper ventilation, covers,

mattress and isolation. The use of cradles declined as the use of cribs increased,

the design of which was widely discussed in magazines in the 1920s and 1930s.

Children were also moved to separate bedrooms when housework became noisier

due to vacuum cleaners and sewing machines, noise from the radio, and more

vivid lighting due to electricity. (Stearns et al. 1996.)

During this time, in 1920, a pediatrician called Arvo Ylppö had as him aim to

reduce high infant mortality in Finland by distributing childcare guidelines to

mothers (Ylppö 1921). Poor air quality inside the home, preventing rickets and

creating sound blood were reasons why the childcare practice of having children

sleep outdoors was recommended. Fresh and cold air was thought to increase

blood circulation in the linings of the nose and mouth and thus increase immunity

to bacteria. Sunlight was thought to be an important preventive factor against

diseases as well. Infants were able to get wind, fresh air and sunlight in their faces

without any harm if they were regularly familiarized with cold air at an early

stage. (Ylppö 1939.) Only newborn children were regarded as too sensitive to

cold, but infants only a few weeks old were already allowed to sleep outside

without worrying at temperatures of −10°C…−15°C (Ylppö 1947). At the

beginning of the 20th century it was not so common to see children sleeping

outdoors during the winter. Public health nurses met children who had not been

outdoors during the first year of their lives. There were not enough clothes for the

children, and the few garments there were made of adults’ old ones. Children had

to be outdoors by turns due to lack of shoes. (Punto 1991.)

Public health nurses first had to disseminate the bases of the importance of

outdoor sleeping on a child’s health and well-being in the 1940s and 1950s; after

that, they changed the emphasis of counseling from stressing the importance of

outdoor sleeping to practical instructions and advice about duration and suitable

25

clothing in the 1960s (Varjoranta 1992). The viewpoint that mothers should put

their children outside to sleep was disseminated in parenting manuals and

information was distributed by public health nurses, so that parents adopted the

practice in their everyday lives. Little by little experience and social knowledge

has increased. Today, the practice of children sleeping outdoors is common in the

Nordic countries, being most common in Denmark and Finland (Reima group

2009). In the study by the Reima group (2009), most Finnish parents thought that

it is very important for children to be outdoors every day. As Lipton et al. (1965)

have written: “infant care practices are deeply rooted in culture and represent the

end results of generations of experience and conviction”.

2.4 Cultural clothing practice and thermal resistance

Cultural traditions and beliefs influence the thermal environment in which infants

are cared (Watson et al. 1998, Nelson et al. 2000). For example, infants in Japan

and Korea sleep indoors in bedding combinations of greater insulation than

infants in New Zealand in comparable season (Wilson & Chu 2005). Traditional

outdoor infant care practices, such as swaddling and living in traditional tents

called “Ger” in the Mongolian winter (Tsogt et al. 2006) and using a form of

dressing called “manta pouch” in Peru (Tronick et al. 1994) have been

represented as protecting the infant from the cold.

Swaddling, a form of some degree of infant motor restraint by using bands or

clothes wrapped around an infant was widely used worldwide before the 18th

century (Lipton et al. 1965). Today its prevalence varies in different countries; in

England, for example, it is hardly endorsed (Morrell & Cortina-Borja 2002). van

Sleuwen et al. (2007) have compiled information about swaddling and evaluated

its benefits and disadvantages in their systematic review. Swaddling has been

shown to calm infants; excessively crying infants cry less, it may sooth pain and

increase daytime sleep duration and decrease arousing. It has been suggested that

the restraint of arms may inhibit full extensor movements that startle the infant.

Swaddling has been shown to improve neuromuscular development, motor

organization and ability to self-regulation and increase physiologic distress in

preterm infants. Swaddling can be helpful for temperature control, but it can also

cause risk for hyperthermia when misapplied. Supine position decreases the risk

for SIDS more in swaddled babies than in those without swaddling, but increases

the risk if the baby is overdressed and the head is covered. Other adverse effects

that were mentioned in the review were an increased risk of the development of

26

hip dysplasia, which is related to legs in extension, higher risk of respiratory

infections related to tightness of swaddling and deficiency of vitamin D in some

countries. (van Sleuwen et al. 2007.)

In Finland the outdoor sleeping childcare practice in winter is commonly

endorsed, indicated by the fact that the Social Insurance Institution of Finland

distributes maternity packages including infants’ winter clothing and sleeping

bags to expecting mothers without any charge. The maternity package is common:

annually about 40,000 packages are distributed in Finland. Families have been

very content with the package. (Bogdanoff & Hämäläinen 2011.)

In the study of Wailoo et al. (1989a) parents received advice on how to clothe

their babies from a number of sources, such as other parents and health care

workers, mainly given at the time of birth, whereas in the study of Wigfield et al.

(1993) parents seemed to instinctively provide appropriate thermal conditions for

their infants to sleep in. Correlations were found in both studies with clothing

insulation of infants and room temperature, with parents applying more insulation

on colder nights with lower bedroom temperatures (Wailoo et al. 1989a, Wigfield

et al. 1993), and also applying more insulation in winter than in summer

(Wigfield et al. 1993). Contrary to these studies, some infants had also been

dressed inappropriately indoors when perceptions of expected weather conditions

and temperature outdoors had affected in parents’ decisions when making

assessments of ambient temperature (Nicoll & Davies 1986, Tuohy & Tuohy

1990, Bacon et al. 1991, Wigfield et al. 1993).

According to the study of Eiser et al. (1985), most mothers thought that

infants got colds from other people, but almost half of the mothers felt that infants

could get colds by being cold or wet. Bacon (1983) suggests that although

according to this folklore that infants should be well wrapped to prevent them

from getting a cold, wrapping them well may lead to overheating and fever. On

the contrary, Grover et al. (1994) found that bundling a healthy infant caused a

rise in skin temperature, but not in rectal temperature, suggesting that elevated

rectal temperature should rarely be attributed to bundling, in contrast to infections.

Clothing provides thermal resistance between the child and its environment,

maintaining the body in an acceptable thermal state in a variety of environments.

Thermal insulation is provided by the garments themselves, and especially the air

trapped in them, as well as by the layers of air trapped between the skin and

clothing layers. (Parsons 2003.) When a clothing ensemble consists of many

layers the total insulation is much higher than could be expected from the

insulation of the material layer alone (Havenith 1999). Many factors affect the

27

thermal characteristics of clothing, such as dry thermal insulation, transfer of

moisture and vapor through clothing, heat exchange with clothing, compression,

pumping effects, air penetration and subject posture (Parsons 2003).

2.5 The well-being of children in the north

The concept of well-being is broad and sometimes used as a synonym for health,

quality of life, life satisfaction, wellness and happiness. The definition of health

has shifted away from viewing health in terms of freedom from disease to an

emphasis on the individual’s ability to perform daily activities, and further to an

emphasis on the positive themes of happiness, social and emotional well-being,

and quality of life (McDowell & Newell 1996). Heath is described as an integral

part of the everyday life of families consisting of various dimensions of

experienced well-being and unwell-being, security and different life-habits

(Åstedt-Kurki et al. 1999). The determinants of health can be seen as proximal,

intermediate and distal. Proximal determinants of health include conditions that

have a direct impact on physical, emotional or spiritual health (e.g. health

behaviors, physical and social environment), intermediate determinants can be

seen as the origin of those proximal determinants (e.g. health care systems,

educational systems, community infrastructure, environmental stewardship,

cultural continuity), while distal determinants have profound influence on the

health of populations because they represent political, economic, and social

contexts that construct both intermediate and proximal determinants (e.g. historic,

political, social and economic contexts). (Reading & Wien 2009.) The well-being

of humans is influenced by many factors of the environment as well as a variety

of personal attributes, and that is why promotion of well-being should be based on

an understanding of interplays between these factors, not focusing exclusively on

one just factor (Stokols 1992).

In order to attain an overview of scientific studies related to the well-being of

children in the north, a literature search was performed using the Ovid Medline,

Cinahl, Arctic & Antarctic Regions (EBSCO), and PsycINFO databases. The

search was limited to April 2011 using the following search terms: infant* welfare

/ infant* well-being / child* welfare / child* well-being / toddler* welfare /

toddler* well-being / teen* welfare / teen* well-being / youth welfare / youth

well-being / adolescent* welfare / adolescent* well-being / famil* welfare /

famil* well-being / social welfare (limit all child or family) AND arctic / arctic

regions / northern / north / circumpolar / cold / cold climate / polar. Inclusion

28

criteria were as follows: 1) the place where the data was collected was located ≥

60 degrees northern latitude; 2) scientific empirical article or systematic literature

review; 3) the article was in English; 4) an abstract was available; 5) search terms

were included in the title and/or abstract and/or MeSH-term. Altogether 52

articles fulfilled inclusion criteria after duplicates were excluded (Table 1).

Table 1. The result of literature search related to the well-being of children in the north

by different databases.

Database Potentially relevant citations (n) Studies meeting inclusion criteria (n)

Ovid Medline 796 35

Cinahl 172 2

Arctic & Antarctic Regions 211 5

PsycINFO 755 10

The phenomenon of children’s well-being in the north consisted of studies dealing

with five main categories. Health care studies (n = 14) consisted of interventions

concerned for example with the prevention of childhood farm injuries in North

America (Hartling et al. 2004) and outdoor wintertime sun safety education

(Walkosz et al. 2007). Also studies about health services such as children’s use of

general practitioner services in Finland (Vuorinen et al. 1991), and using

telehealth in rural communities in Canada (Ens et al. 2010) were found.

Environmental health studies (n = 12) concerned exposures that were detrimental

to health, such as metals in the soil of children’s urban environment in Sweden

(Ljung et al. 2006) and infants’ blood lead concentrations and iron deficiency in

Canada (Willows & Gray-Donald 2002), as well as associations between diseases

and geographic (Samuelsen et al. 1993) and seasonal variations (Stephenson et al.

2002). Studies about diseases (n = 11) such as allergy in relation to pet ownership

(Braback et al. 2001) and well-being in children with for example symptoms of

ADHD (attention deficit hyperactivity disorder) (Taanila et al. 2009) emerged.

The fourth biggest group comprised studies about lifestyle and health habits

(n = 9). Our study of children sleeping outdoors (Study I) was placed in this

category. No other studies about sleep were found; instead, studies for example

about nutrient intake (Nakano et al. 2005) and life goals among adolescent (Lekes

et al. 2010) were found. The fifth category include children in research (n = 6),

such as ethical, legal and social issues in birth cohort studies (Ries et al. 2010)

and methodological issues in interviewing families (Åstedt-Kurki et al. 2001).

29

The topics of the studies on children’s well-being were versatile. However,

there was a lack of studies about the associations between climatic factors and

child health (Bunyavanich et al. 2003), and especially studies related to children’s

cold exposure in the area of children’s environmental health, even though it

comprises important physical environmental factors, such as air pollution, lead,

chemicals and noise, which all have effects on children’s health (Pond et al. 2007).

Growing evidence can be found that climate-health relationships pose increasing

health risks under future projections of climate change (Patz et al. 2005), and

children are especially vulnerable to these risks because of their greater exposure,

sensitivity, and dependence on caregivers for appropriate preparedness and

response (Sattler 2003, Ebi & Paulson 2007).

2.6 Sleep of children

The development and effects of sleep. During the first years of life sleep patterns

develop fast (Armstrong et al. 1994, Acebo et al. 2005, Sadeh et al. 2009). The

sleep cycles, during which REM (rapid eye movement sleep, active sleep) and

non-REM (quiet sleep) sleep stages alternate, last about 50 minutes in infants,

compared to about 90–110 minutes in adults. Newborn infants’ sleep is different

from that in older children as they fall directly into REM sleep (Hill et al. 2007).

More than half of their sleep consists of REM sleep (Roffwarg et al. 1966, Anders

et al. 1995), which decreases throughout childhood, while non-REM sleep

increases steadily (Roffwarg et al. 1966).

Multiple sleep periods around the clock consolidate progressively to one

main continuous nighttime sleep (Burnham et al. 2002) and well-defined daytime

naps by about three months of age (Parmelee et al. 1964). At about six months of

age the sleep cycle starts with non-REM sleep and infants have learn to move

from one sleep phase to another without waking (Hill et al. 2007).

Three-month-old children still spend most of their time sleeping; total sleep

duration is about 14.5 hours and daytime sleep duration about 4.5 hours

(Iglowstein et al. 2003, Sadeh et al. 2009) divided into two or more naps per day

(Iglowstein et al. 2003). Children usually give up taking daytime naps between 3

and 5 years of age, but some children not until the age of 7 (Weissbluth 1995,

Iglowstein et al. 2003) or later (Crosby et al. 2005). Total sleep duration

continues to decrease from about 14 hours at 6 months of age to about 8 hours at

16 years of age (Iglowstein et al. 2003). However, large individual variation can

be found in sleep duration especially during the first year of life (Iglowstein et al.

30

2003, Sadeh et al. 2009) indicating variability in sleep need or sleep opportunity

(Sadeh et al. 2009).

It has been hypothesized that sleep has a restorative effect on brain

metabolism and effects on memory consolidation, learning (Maquet 2001, Gómez

et al. 2006), as well as emotion and behavior regulation (Bates et al. 2002, Ward

et al. 2008). Sufficient sleep quantity and good sleep quality have been associated

with higher levels of optimism and self-esteem, thus affecting well-being in

children (Lemola et al. 2011). Reduced total sleep time might cause adverse

effects on normal cognitive (Dahl 1996) and social development (Lavigne et al.

1999). Daytime sleep has been shown to have similar beneficial effects on visual

learning as sleeping during the night among adults (Mednick et al. 2003), and

infants’ daytime sleep has appeared to promote abstraction in learning of

language (Gómez et al. 2006). Wake et al. (2006) found that most sleep problems

in the first two years of life are transient, but infants’ sleep problems have also

been associated with neurodevelopmental disorders later in childhood (Thunström

2002), and sleep problems in childhood may even associate with poor psychiatric

state in adulthood (Gregory et al. 2005). Less sleep during infancy has been

associated with weight gain and obesity in infants (Tikotzky et al. 2010), in

preschool-aged children (Taveras et al. 2008) and in adulthood (Landhuis et al.

2008).

The transactional model of sleep in socio-cultural contexts. In their

transactional model of sleep-wake regulation Sadeh & Anders (1993) have

emphasized that infants need to be viewed as part of a system where bidirectional

links between parenting and infant sleep can be seen. Infants’ sleep is affected by

maturational, intrinsic constitutional, biological, temperamental and medical

factors affect, but also by parental interactive behaviors. Parents’ socio-cultural

and environmental context, developmental history and memories, personality and

psychopathology as well as infant’s age, developmental characteristics and sleep

patterns affect parents’ beliefs, expectations, emotions and behaviors related to

infants’ sleep. (Sadeh et al. 2010.)

According to the transactional model, infants’ sleep, parenting competence

and well-being are influenced by complex relationship systems (Sadeh et al.

2010). Maternal cognitions about difficulty with limit setting, anger at the infant’s

demands, and increased doubts about parenting competence have been

significantly associated with infant sleep problems by Morell (1999). Parents

have experienced low efficacy related to infants’ daily rhythm and sleep (Salonen

et al. 2008) and during the stage when sleep patterns are developing, sleep

31

problems are a major issue of concern to parents (Sadeh & Anders 1993, Morrell

1999, Thunström 1999, Lam et al. 2003, Wake et al. 2006, Bayer et al. 2007,

Martin et al. 2007) in many cultures (Mindell et al. 2010b). Cultural norms affect

definitions as to what can be seen as normal or problematic sleep behavior (Jenni

& O'Connor 2005).

In addition to the direct effects of sleep problems to infants, they may also

cause adverse effects in a broader context. Infants’ sleep problems have been

associated with mothers’ depression (Armstrong et al. 1998, Hiscock & Wake

2001, Lam et al. 2003, Bayer et al. 2007), poorer general health in both mothers

and fathers (Martin et al. 2007) and parents’ marital conflicts (Richman 1981, El-

Sheikh et al. 2006, Meijer & van den Wittenboer 2007). However, in the study of

Lam et al. (2003) families functioned well despite having children with sleep

problems that resulted in an increase in maternal depressive symptoms.

Schwichtenberg et al. (2011) found in their study that those infants who took

more naps experienced more positive maternal affect, involvement, and

verbalizations. Sleeping more during the daytime may give infants and their

mothers a break, promoting optimal parenting. (Schwichtenberg et al. 2011.) It

has been shown that it is possible to reduce maternal symptoms of depression by

using behavioral infant sleep improving interventions (Hiscock & Wake 2002). In

general, infants’ sleeping problems cause substantial costs to health services

(Morris et al. 2001).

The method of falling asleep and sleep location have been shown to predict

sleep duration (Sadeh 2004). Parental involvement at bedtime has been correlated

with an increased number and duration of night waking of infants (Touchette et al.

2005, Sadeh et al. 2009, Tikotzky & Sadeh 2009), and infants who sleep in a crib

in a separate room have been reported to have fewer night wakings and shorter

settling times (Sadeh 2004). High level of parental interactions and soothing

routines are assumed to prevent infants from developing their own self-regulation

and self-soothing skills, resulting in shorter and more fragmented sleep (Sadeh et

al. 2010). Parenting practices that encouraged infants to independence and self-

soothing were associated with extended and more consolidated sleep by Sadeh et

al. (2009) in a study where a large (5,006 infants and toddlers) sample from the

United Stated and Canada was examined. Moreover, as bidirectional links exist

between parenting and infant sleep, interpretations that infants with sleep

problems require more parental involvements have also been presented (Tikotzky

& Sadeh 2009). According to McKenna et al. (2007) and McKenna & Volpe

(2007), expectations of self-soothing of infants and sleeping separately from

32

parents do not promote infants’ biological and emotional needs. Bedsharing has

been described to enhance the emotional connection between mother and infant

(Abel et al. 2001, McKenna & Volpe 2007), when infants need comfort and

regulation from their parents especially during the first months of life (Anders

1994).

The socio-cultural context has an important role in shaping parental

expectations and practices (Sadeh & Anders 1993, Sadeh et al. 2010). Cultural

norms, ethnicity and background may influence for example whether certain sleep

behaviors among children are determined as problematic (Jenni & O'Connor 2005,

Mindell et al. 2010b, Sadeh et al. 2010) and what is regarded as an appropriate

sleep environment (McKenna et al. 2007). Mindell et al. (2010a) provided a

picture of parenting and sleep ecology using a large global sample of parents of

29,287 infants and toddlers from predominantly Caucasian (Australia, Canada,

New Zealand, United Kingdom, and United States) and predominantly Asian

(China, Hong Kong, India, Indonesia, Japan, Korea, Singapore, Malaysia,

Philippines, Taiwan, Thailand, and Vietnam) regions. Striking cultural differences

were found, as 57% of children in predominantly Caucasian regions fall asleep

independently, compared to 4% of children in predominantly Asian regions

(Mindell et al. 2010a), who also had later bedtimes, shorter total sleep times,

increased parental perception of sleep problems, and were more likely to bed-

share and room-share. Minimal differences were found for daytime sleep with all

children (Mindell et al. 2010b).

Cultural values, parental expectations and infant’s developmental needs affect

the distance between the sleep locations of parents and infant; physical proximity

ranges from cosleeping in the same bed to sleeping independently in a separate

room. According to the findings of Nelson et al. (2000) 23 of 26 nonindustrialized

societies used separate beds for their infants (cradles, cots, mats, or hammocks) in

which the baby was placed during the day. According to the study of Morelli et al.

(1992), Mayan parents, who let their children sleep in their mothers’ bed,

described it in terms of the value of closeness with the baby, regarding the U.S.

families’ practice of having babies sleep in separate rooms as “tantamount to child

neglect” (Morelli et al. 1992), whereas having babies sleep in a separate room

was explained by the mothers from the U.S. to be of value for babies’

independence (Morelli et al. 1992, Germo et al. 2007). According to Anders &

Taylor (1994) many U.S. families shortened this distance by using baby monitors

designed to help parents hear their children sleep.

33

Seasons and children’s sleep. Few studies can be found comparing physical

environmental factors, such as seasons with children’s sleep. In the study of Javo

et al. (2004) cross-cultural differences in parenting among Sami and Norwegian

parents of four-year old children were studied. They found that compared

Norwegian mothers, Sami mothers regulated their children’s bedtime more

according to the season, letting children stay up much longer during the summer.

Carscadon & Acebo (1993) have described in their study parental reports of

seasonal mood and behavior changes in children aged about ten, some of whose

sleeping times were described as lengthening in the fall and winter.

Seasonal variation in sudden infant death syndrome (SIDS) with winter peaks

has been reported in both the northern and southern hemispheres in several

countries, such as Norway (Vege et al. 1998, Arnestad et al. 2001), Sweden

(Milerad et al. 1993, Haglund et al. 1995), Britain (Douglas et al. 1996, Douglas

et al. 1998), Ireland (Douglas et al. 1998), Italy (Montomoli et al. 2004), New

Zealand (Schluter et al. 1998), the United States (Malloy & Freeman 2004)

Hawaii (Mage 2004), California (Chang et al. 2008) and Ohio (Strimer et al.

1969), Kuwait (Douglas & Al-Sayer 1991) and Israel (Sivan et al. 1992). Outdoor

sleeping was mentioned in only three studies, where more deaths occurred

indoors compared with deaths occurring outdoors (Milerad et al. 1993, Vege et al.

1998, Arnestad et al. 2001), the proportion of which fluctuated from 40% to 9%

over different time periods. Outdoor deaths were more common during the winter

than during the summer. (Milerad et al. 1993, Vege et al. 1998.) Sleeping in prone

position is known to be a major cause of SIDS (Gilbert et al. 2005), and prone

sleeping has been associated with a greater risk in winter than in summer

(Mitchell et al. 1999). The seasonal variation of SIDS has also been associated

with cold meteorological temperature (Jones et al. 1994, Leiss & Suchindran

1996), but not with Föhn winds (Macey et al. 2000), thermal stress due to excess

thermal insulation (Nelson et al. 1989, Fleming et al. 1990) or having the head

covered (Beal 2000), viral infection (Harrison et al. 1999, Lindgren 1999), or

outdoor air pollution (Hoppenbrouwers et al. 1981, Klonoff-Cohen et al. 2005)

with highest levels in the winter (Hoppenbrouwers et al. 1981). However, a trend

of a diminishing rate of seasonal variation has been seen (Arnestad et al. 2001,

Malloy & Freeman 2004, Chang et al. 2008).

A literature search was performed using the Ovid Medline, Cinahl, Arctic &

Antarctic Regions (EBSCO), and PsycINFO databases in order to ensure a broad

scope of the literature in addition to articles gained through manual searches. The

search was limited to April 2011 using the following search terms: cold

34

temperature, arctic regions, cold climate, arctic, circumpolar, polar, north, cold

AND child*, infant*, toddler*, babies, baby AND sleep*, nap. Scientific

empirical articles or systematic literature reviews written in English were

included, and after duplicates were excluded, 29 articles fulfilled inclusion criteria

(Table 2). The included articles were related to thermal environment,

thermoregulation and/or circadian rhythm of infants (n = 15), sudden infant death

syndrome (n = 10) and child care (n = 4).

Table 2. The results of the literature search related to children’s sleep by different

databases.

Database Potentially relevant citations (n) Studies meeting inclusion criteria (n)

Ovid Medline 192 14

PsycINFO 564 7

Cinahl 68 1

Arctic & Antarctic Regions 110 7

2.7 Thermal environment of children

2.7.1 Thermal balance and thermoregulation

Thermoregulation is physiological ability to maintain body temperature within a

restricted range under conditions involving variable internal and external heat

loads (IUPS Thermal Commission 2001). Human response is influenced by air

temperature, radiant temperature, humidity and air movement, which constitute

the basic environmental parameters. Human activity and clothing are the personal

factors that influence the heat loads (Parsons 2003). The relationship with heat

production and heat transfers between the body and environment can be viewed

as heat balance equation (Parsons 2003, ISO 11079 2007):

M – W = E + R + C + K + S [W/m2],

where M is metabolic rate, which provides energy to do mechanical work (W).

The rest of the energy is released as heat. The body loses heat by radiation (R)

from the skin and by the evaporation (E) of water from the skin and the

respiratory tract. Heat is also lost to cooler environment by convection (C). Heat

loss to cooler objects in direct contact is conductive (K) heat flow, which becomes

a relevant factor when infants sleep in supine position. The sum of heat

production and loss provides the body heat storage rate (S), which is zero in heat

35

balance, positive in heat gain and negative in net heat loss. The heat balance

equation describes how the body can maintain a core body temperature (Parsons

2003), which in low birth weight infants at rest should be between 36.7 and

37.3°C, and the core temperature and Tsk change less than 0.2 and 0.3°C/hour,

respectively, in thermoneutral ambient temperature. When the infant becomes

older and the body weight increases, the temperature of a neutral thermal

environment decreases (Sauer et al. 1984). Also interindividual variability (Bach

et al. 2000a), metabolic rate (oxygen consumption) (Hey & O'Connell 1970) and

sleep variables, which are more sensitive to a mild cold exposure (Telliez et al.

1997, Bach et al. 2000a), should be observed when defining thermoneutrality.

Temperature regulation processes are activated when the environmental

temperature is not in the thermoneutral zone (Parsons 2003).

Removal to a relatively cold environment at birth causes temperature drops in

neonates, and increased heat production is essential for survival. The temperature

regulation response begins within minutes of birth, with oxygen consumption and

heat production increasing two- to three-fold. Basic heat production is generated

through metabolic activity and additional heat production through shivering and

nonshivering thermoregulation. (Asakura 2004.)

Newborn infants’ primary source of heat production is based on nonshivering

thermogenesis in brown adipose tissue (BAT), which is mainly located in the

interscapular region, neck, between the ribs and around the kidneys, serving as a

warming mechanism for the blood supply of vital organs (Aherne & Hull 1966,

Wehrli et al. 2007). The activation of nonshivering thermogenesis is dependent on

oxygen supply and thus it results in an increase in oxygen consumption

(Schubring 1986). Because of reduced demands for nonshivering thermogenesis

when shivering takes place, the importance and prevalence of BAT diminishes

with age (Johansson 1959, Wehrli et al. 2007). In the study of Hassi (1977) the

prevalence of BAT was about 90% in the samples from study children from the

fetal stage to the age of one year, diminishing to 43% in 1- to 13-year-old children,

when for example only single brown adipose cells or cell clusters were found in

the interscapular adipose tissue. Aherne and Hull (1966) have also suggested that

infants cared for in an ambient temperature lower than neutral may have gradual

depletion of BAT. The heat production increase cannot be continued in prolonged

cold exposure (Bach et al. 1994, Bach et al. 2002), but it has also been suggested

that the thermal resistance of neonates is improved by prolonged exposure to a

cool environment (Glass et al. 1968, Perlstein et al. 1974).

36

Infants are at increased risk of heat loss due to a large surface area in relation

to weight, a thin insulating fat layer and poor shivering mechanism (Pocock et al.

1999) due to relatively immature skeletal muscles (Herpin et al. 2002, Asakura

2004). Shivering has only been observed in infants when the body temperature

has decreased considerably (Darnall 1987) or in extreme cold exposures

(Adamson et al. 1965). Temperature sensitive receptors have been identified in

the skin, hypothalamus, spinal cord, blood vessels and in other body regions

(Hensel 1974), being either warm or cold types and sending signals to the

hypothalamic thermoregulatory center (Parsons 2003). According to Mestyàn et

al. (1964), the skin on infants’ face is sensitive to environmental temperature

changes, so that cooling of the face increases oxygen consumption.

Heat is transferred from the deeper tissues of the body to the surface of the

body where it can be lost to the environment. Vasoconstricted skin creates more

effective insulation compared with vasodilated skin. When the body becomes cold,

the heat is preserved by vasoconstriction, and if necessary, heat is generated by

shivering and nonshivering, whereas when the body becomes hot it loses heat

through vasodilation, and if required, through sweating. (Parsons 2003.) Skin

blood flow is well developed in infants (Hey 1972); in very low birthweight

infants it develops over the first two to three days of life (Lyon et al. 1997).

Cooling-induced vasoconstriction first takes place in peripheral vessels, seen as

falling skin temperatures in the extremities (Wissler 2008), and thus central-

peripheral skin temperature difference can be used as an indicator of cold stress

(Lyon et al. 1997). Skin temperatures in the extremities and trunk have been

shown to fall sharply in a heat-losing cool environment in infants, whereas the

temperature of the nape remains warmer because it contains brown adipose tissue

(Silverman et al. 1964, Rylander et al. 1972). Tsuzuki et al. (2008) found that

children had a greater decline in skin temperature of the hand and foot than adults

during exposure to cold, suggesting greater vasoconstriction in children.

Newborns are able to exhibit behavioral responses by changing posture and

modifying the body surface area exposed to the surroundings, thus changing

convective and radiative heat loss; e.g. crouch prone position reduced the body

surface area to 69% in cool environment (Stothers & Warner 1984).

Already a small 1.5°C decrease below thermoneutrality in air temperature has

been shown to affect body temperature, sleep, and restlessness without increase in

VO2 (oxygen consumption) (Bach et al. 2000a), suggesting that peripheral and

central thermal responses are evoked in cool exposure, but are not large enough to

induce heat production in brown adipose tissue (Telliez et al. 1997).

37

In a warm environment, sweat is secreted over the skin to allow cooling by

evaporation (Parsons 2003). The sweat gland density in infants is larger than in

adults, but the sweating response is much more ineffective. Sweating nearly

always occurs first, and profusely, on the head, accounting for 85% of the total

body heat loss in supine position; the trunk and limbs start sweating later. (Foster

et al. 1969.) The threshold is lower for the rate of fall than the rate of rise in skin

temperature (Libert et al. 1979) when all body sites are more sensitive to cold

than to warm (Stevens & Choo 1998).

When Eiser et al. (1985) asked mothers how they checked whether the baby

was too hot, most mothers relied on feeling the baby or checking the baby’s color.

Some mothers mentioned also that the baby become irritable if too hot or were

sweaty. Only few mothers used their own feelings of hot as a guide to the baby’s

temperature. It was more difficult for mothers to estimate whether the infant was

too cold. Almost all mothers felt the baby while others relied on color or observed

when the baby became irritable when too cold.

2.7.2 Interaction between sleep and thermoregulation

Wailoo et al. (1990) suggest that thermal discomfort could cause awakenings in

infants as some poorly wrapped babies woke early, and especially heavily

wrapped babies in warm rooms did so even more frequently. According to other

studies, exposure to warm temperature did not disturb sleep, but the duration of

REM sleep has been observed to increase in a cold environment (Bach et al. 1994,

Telliez et al. 1997, Bach et al. 2000ab, Bach et al. 2001, Telliez et al. 2004) at the

expense of non-REM sleep (Azaz et al. 1992, Telliez et al. 1997, Bach et al.

2000ab, Bach et al. 2001, Telliez et al. 2004), decreasing the total sleep time

(Telliez et al. 1997, Bach et al. 2000ab, Bach et al. 2001). Cold exposure delays

sleep onset (Bach et al. 1996) and enhances awakenings (Azaz et al. 1992, Telliez

et al. 2004).

It has been found that overall sleep movements decrease in warm conditions

(Bach et al. 1994), while small body movements increase during cold exposure

(Hey 1969, Azaz et al. 1992, Bach et al. 1994, Telliez et al. 1997, Bach et al.

2000a), often causing the lightly clothed infant to wake up, especially at 1 to 3

months of age (Azaz et al. 1992) and during REM sleep (Bach et al. 1994). This

is in contrast to the findings of Hey & O’Connell (1970) where clothed infants did

not cry or move in response to cooling.

38

Higher levels of VO2 have been found due to larger metabolic heat

production during REM sleep than during non-REM sleep in short cool exposure

suggesting that thermoregulation could be maintained mainly by vasoconstriction,

but partly also by increasing REM sleep (Telliez et al. 2004), the

thermoregulation of which is not impaired, as it is in adults (Bach et al. 1994,

Telliez et al. 2004).

Infants sleeping in the prone position have been found to have a lower

metabolic rate than those sleeping in the supine position (Ammari et al. 2009),

although infants in the supine position have lower heart rate and peripheral skin

(Skadberg & Markestad 1997, Ammari et al. 2009) and rectal temperature (North

et al. 1995). According to the findings of Baddock et al. (2004), bed-sharing

infants experienced warmer thermal conditions than cot-sleeping infants, but they

were still able to maintain a normal core temperature.

Apneas have been observed more frequently in warm conditions than during

exposure to cool temperatures (Bach et al. 1994). It has also been found that

infants’ auditory thresholds increased in warm rooms (Franco et al. 2001) and

when the face was covered (Franco et al. 2002).

The biorhythm is immature in newborns and requires functional maturity of

the central nervous system components. Parents and other family members in a

home environment are governed by the circadian rhythm, and it is an important

developmental step for the newborn baby to fit into this tempo. (Thomas & Burr

2002.) The daily body temperature rhythm develops earliest (McGraw et al.

1999). According to the findings of Lodemore et al. (1991), rectal temperature

changed little in the first two weeks of life, but by 6 weeks of age rectal

temperature was higher at bedtime than later in the night, and those whose rectal

temperature fell below 36.5°C also slept longer. The fall has been shown to be

greater during nighttime sleep than during the day, even when infants have had

similar sleep durations (Anderson et al. 1990). The characteristic pattern of

decreased nighttime deep body temperature is exhibited by infants by 4 months of

age (Wailoo et al. 1989b, Lodemore et al. 1991, Lodemore et al. 1992); this rate

of fall is unaffected by environmental conditions (Wailoo et al. 1989a, Anderson

et al. 1990). Skin temperatures change less than rectal temperature during nights

(Wailoo et al. 1989b); for example, no significant circadian variation rhythm in

abdominal skin temperature was found in the study of Glotzbach et al. (1994).

39

2.7.3 Symptoms of thermal stress

Neonatal hyperthermia can develop when the infant is in an environment that is

too hot and the core body temperature rises above 37.5°C. This should be

differentiated from fever caused by infection with microorganisms or other

sources of inflammation. Hyperthermia is less frequent than hypothermia,

although both situations can occur equally easily in neonates. (World Health

Organization 1997.) Overheating has been associated with increased risk for

SIDS, and it has been suggested that cultural child care practices may facilitate

hyperthermia, partly causing the disparate rates of SIDS in different countries

(Nelson et al. 1989, Ponsonby et al. 1992).

The newborn can be defined to be under cold stress when a body temperature

is 36.0–36.4°C, under moderate hypothermia with a temperature of 32.0–35.9°C,

and severe hypothermia with a temperature below 32°C (World Health

Organization 1997). Hypothermia has also been defined as a core body

temperature of 35°C or lower (Culic 2005). Accidental hypothermia called cold

injury syndrome (CIS) has been described to exist in neonates and infants due to

exposure to cold (Mann & Elliot 1957). Children with CIS have had cold skin and

limbs along with red facial skin and some of them have been sleepy, hypotonic

and inactive. Most of those patients have also been cyanotic with bradycardia and

bradypnea, and have had scleredema (Culic 2005). In a 10-year cohort study

between 1976 and 1985 in Croatia by Culic (2005), 103 children, most of them

between 0–15 days old, were diagnosed with CIS. Behavioral customs and

insufficient home heating could have affected the frequency of CIS when most of

the children were hospitalized in the winter. The frequency of CIS in Split has

decreased, as only 5 infants were hospitalized between 1991 and 1995. (Culic

2005.) Neonatal hypothermia has also been reported to exist in many other

countries (Goldsmith et al. 1991), being a common problem especially in

developing countries (Dragovich et al. 1997). In Ladakh, India, most of the

pediatric hospital deaths have been reported to occur in the winter months (Wiley

2004).

According to Glass et al. (1968), the rate of increase in body weight and

length among newborn infants was faster in warmer conditions. Hypothermia

may cause psychological and neurodevelopmental disturbances (Culic 2005) and

it is associated with increased morbidity for example from infections (Dagan &

Gorodischer 1984), and it has been seen as a contributing factor to mortality

40

among newborns (Mann & Elliot 1957) and premature infants even in mild cold

stress (Day et al. 1964).

Chilblains, also known as pernio, are a moderately severe form of cold injury

characterized by localized inflammatory skin lesions with cyanosis and

subcutaneous swelling in areas exposed to prolonged nonfreezing temperatures

and damp conditions (Long et al. 2005). Chilblains are usually located in the

peripheral parts (fingers, toes, and ears) of the body (Weston & Morelli 2000,

Gardinal-Galera et al. 2010), but chilblains have also been found on the cheek of

a child (Giusti & Tunnessen 1997). Color changes (white, blue, red) of the distal

extremities in response to cold are defined as Raynaud’s phenomenon, the

symptoms of which can begin in childhood (Nigrovic et al. 2003, Tsai et al. 2010).

Due to an oversensitive reaction to cold by vasoconstriction and thus reduced

circulation in peripheral parts of the body, people with Raynaud’s phenomenon

have an increased risk of frostbite, among other physiological, behavioral and

environmental factors predisposing for frostbite (Rintamäki 2000).

When the temperature of tissue is reduced below the freezing point, frostbite

emerges, producing localized necrosis. Although children are particularly

vulnerable to cold injury and frostbites, only few cases have been reported

(Brown et al. 1983, von Heimburg et al. 2001, Krishnamurthy et al. 2009).

Gangrene resulting from frostbite in neonates is an extremely rare event

(Krishnamurthy et al. 2009). In the study of Koljonen et al. (2004) where

frostbite injuries in the Helsinki area from 1995 to 2002 were studied, children

under 13 were not mentioned. Instead, Juopperi et al. (2002) studied the incidence

of patients admitted to hospitals in Finland with frostbite during the period 1986–

1995 and found that frostbites increased linearly with age: 0.9% (n = 11) of the

patients who were 0–9 years old and 8.3% (n = 106) of the patients who were 10–

19 years old had frostbites, respectively. Frostbites in childhood can cause long-

term consequences in the joints and bones (Brown et al. 1983, Ervasti et al. 1993).

Because of the importance of thermoregulation in infants the World Health

Organization (1996, 1997) has published some information for the prevention of

hypothermia aimed at health professionals as well as parents.

2.8 Summary of the literature

Environment can be viewed as a multilevel context (Bronfenbrenner 1979, Kim

2000), which creates affordances and demands acting as cues for place-related

behavior (Miller et al. 1998). Cultural context shapes parental expectations and

41

childcare practices influencing infants’ clothing, sleep and thermal environment.

Infant’s sleep has broad effects on the family well-being. Infants are a vulnerable

population group due to their fast developing sleep patterns and special

characteristics of thermoregulation. This study is based on the view of multilevel

context (Figure 1).

Fig. 1. The childcare practice of children sleeping outdoors is viewed within a

multilevel context.

Level IChildsleep,

thermoregulation

Level IIClothing

Level IIIFamily

Level IVCulture

Level VNorthern environment

42

43

3 Aims and hypotheses of the study

The purpose of the study was to create a comprehensive view and add

understanding about the childcare practice of children sleeping outdoors in the

context of Northern Finnish winter in order to enhance the well-being of children

and families.

The detailed aims, research questions and hypotheses were as follows:

1. To describe and create a general view of the childcare practice of children

sleeping outdoors in winter in Northern Finland.

a) What is the childcare practice of children sleeping outdoors like?

(Studies I, IV)

b) How prevalent is the childcare practice of children sleeping outdoors in

the city of Oulu? (Study I)

c) Why do parents let their children sleep outdoors in winter? (Studies I, IV)

d) What is the meaning of the childcare practice of children sleeping

outdoors? (Study IV)

2. To describe the relationships between thermal environment, infants’ skin

temperatures and daytime outdoor sleep duration in the northern winter

climate.

a) Hypothesis: Duration of infants’ daytime sleep is longer outdoors in the

winter compared with the daytime sleep they take indoors (Studies I, II).

b) Hypothesis: Infants wearing conventionally used thermal insulation have

lower skin temperatures at the end of outdoor sleep than at the end of

indoor sleep (Study II).

3. To evaluate the thermal insulation of the clothing of infants sleeping outdoors

in the northern winter climate.

a) Hypothesis: Deficiency in thermal insulation increases in colder ambient

air temperatures while overdressing increases in warmer ambient air

temperatures (Study III).

b) Hypothesis: Conventional winter clothing of infants does not ensure

thermal balance during outdoor sleeping (Study III).

44

45

4 Methodology

4.1 Mixed methods research design

There is a complex human environment surrounding this study phenomenon. In

health research various levels of human environments can be found from

immediate to more distant environments, emphasizing the need to use

multidisciplinary and multimethod analyses (Stokols 1992) and more complex

research designs to capture the complexity of human phenomena (Sandelowski

2000). A multidisciplinary mixed methods research design has been used in this

study in order to provide a more comprehensive view and better understanding of

the study phenomenon than would have been provided by single methods alone

(Creswell & Plano Clark 2007, Denscombe 2008). Mixed methods allow the use

of all methods possible, both qualitative and quantitative, to address the research

problems and questions. Both numbers and words are important and necessary to

clarify subtleties and provide a broader perspective on the research topic of this

study. (Creswell & Plano Clark 2007.) Pragmatism as a paradigm is associated

with mixed methods research. It is a pluralistic worldview that is focused on the

consequences of actions, real-world practice-oriented, and problem-centered.

(Tashakkori & Teddlie 1998, Creswell 2003, Creswell & Plano Clark 2007,

Denscombe 2008.)

Mixed methods consist of four major types: triangulation, embedded,

explanatory, and exploratory design. The division is dependent on the timing,

weighting and mixing decisions between qualitative and quantitative methods. In

this study, triangulation has been used due to concurrent timing in qualitative and

quantitative data collection. (Creswell & Plano Clark 2007.) In addition,

sequential timing has been used in quantitative studies, where the pilot study

(Study I) gave rise to the hypothesis that was tested in the next quantitative study

(Study II), while the hypothesis that emerged there was tested in the next study

(Study III). Quantitative methods have been used in Studies I–III, and qualitative

methods mainly in Study IV, and partly in Study I (Figure 2). The findings of the

pilot study (Study I) were also used as an aid in sampling when participants were

screened for inclusion in the interview (Study IV) (Denscombe 2008).

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(qual) methods have been used, as well as data triangulation, due to the variety of

data (time, space and person) (Patton 1990, Kimchi et al. 1991) (Figure 2).

46

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47

Qualitative methods have been used to understand the broader context of the

childcare practice of children sleeping outdoors in winter by paying attention to

the voice of the parents who let their child sleep outdoors. Study IV provides a

culturally sensitive subjective point of view. Quantitative methods have been used

to obtain an objective view of interaction between the child and winter

environment. Both methods have been given equal weight when qualitative and

quantitative data have been analyzed separately and merged together during the

interpretation in the summary.

The childcare practice of outdoor sleeping in winter comprises five levels,

from microlevel to a more distant cultural and environmental level, as well as

interactions between these levels. Although the phenomenon is described as levels

within each other, all levels also have a direct contact to the child. The northern

winter environment has been in evidence in all Studies I–IV. Study results are

presented according to these levels. (Figure 3.) The triangulation design-

multilevel model has been used in order to form a general view of the system by

collecting different types of data from different levels of the system (Creswell &

Plano Clark 2007).

Fig. 3. The phenomenon of outdoor sleeping childcare practice and the studies

involved.

Level IChild

Level IIClothing

Level IIIFamily

Level IVCulture

Level VNorthern environment

Study II

Study I Study III

Study IV

48

4.2 Subjects and settings

Study I was carried out as a questionnaire study in the city of Oulu in November

and December 2004. The questionnaire was distributed to the parents of children

under 2 years of age using the services of child health clinics. Background

information of the study families (n = 116) is presented in Table 3.

The persons interviewed in Study IV between 2007 and 2010 were mothers

(n = 21), who described their family as consisting of themselves, husband (90%)

and 1 to 10 children aged between 2.5 months and 21 years. They lived in

Northern Finland (Kainuu region, Northern Ostrobothnia and Lapland) in towns

(33%), in municipal centers (43%) and in the countryside (24%). Some families

had earlier lived in southern parts of Finland and the USA. The families selected

to Study IV had similar characteristics and backgrounds as those who participated

in Studies I–III.

Physiological measurements of the infants and measurements of

environments (Studies II–III) were conducted in the natural settings of the

families’ homes in town and country settings in Northern Finland (Kainuu region,

Northern Ostrobothnia and Lapland) between January and March 2007 and

between December 2007 and March 2008. Thirty-four families (Table 3)

participated; 33 infants during both outdoor and indoor daytime sleep and one

during outdoor sleep only.

A baby-size thermal manikin (Kyoto Electronics manufacturing Co., Ltd) was

used for the calculations of the insulation of clothing ensembles in the thermal

chamber at the Research Center for Human Environment Adaptation at the

Faculty of Design, Kyushu University, Fukuoka, Japan in December 2008. The 8-

segmented manikin represented an about 4-month-old infant with a body surface

area of 0.311 m2, a weight of 5.7 kg, and height of 60 cm.

49

Table 3. Background information of the subjects in Studies I–III (n, %).

Background variables Study I Study II, III

Mother Father Mother Father

n (%) n (%) n (%) n (%)

Age

20–29 67 (58) 54 (47) 15 (44) 11 (33)

30–39 46 (40) 50 (44) 17 (50) 18 (55)

40–60 3 (2) 10 (9) 2 (6) 4 (12)

Education

No occupational education 13 (11) 6 (5) 2 (6) 1 (3)

Occupational education 26 (23) 43 (39) 8 (24) 15 (47)

Polytechnic school 43 (37) 25 (23) 12 (35) 7 (22)

University 34 (29) 36 (33) 12 (35) 9 (28)

Number of children Family

1 58 (50) 14 (41)

2–3 49 (42) 16 (47)

4–9 9 (8) 4 (12)

Housing

Apartment building 51 (44) 9 (27)

Semi-detached or terrace house 47 (41) 10 (29)

One-family house 17 (15) 15 (44)

Country where the family had lived

Only in Finland 99 (86) 28 (82)

In the Nordic countries 3 (3) 2 (6)

In other countries 13 (11) 4 (12)

Characteristics of the infant Infant

17/17

14.3 (3)

60.9 (3.9)

6215 (1001)

Gender girl/boy

Age (weeks, mean, (SD)

Height (cm, mean, (SD)

Weight (g, mean, (SD)

4.3 Procedures, data collection and analysis

4.3.1 Children sleeping outdoors in winter from the viewpoint of parents

Parents’ opinion, attitudes, beliefs and experiences about the childcare practice of

children sleeping outdoors in winter were studied quantitatively and qualitatively.

Data were collected using a questionnaire compiled for the purpose (Study I) and

by interviewing mothers (Study II).

50

The questionnaire was developed by interviewing four parents who had

experiences about this childcare practice and by using theoretical background

information and questionnaires (Raatikka et al. 2001) designed for adults and

adolescents to obtain information about cold exposure. The questionnaire was

evaluated by a researcher specializing in cold exposure and tested by bachelor’s

degree students (n = 15) from the Department of Nursing Science and Health

Administration at the University of Oulu.

The questionnaire consisted of three items: the background information of the

family (7 questions), children’s outdoor sleeping practices during the winter (23

questions) and parents’ opinions and grounds for having the child sleep outdoors

in the winter (21 statements). A description of variables is given in Publication I

as appendices. The questionnaire includes Nominal, Interval and Likert Scales as

well as open questions.

The questionnaires were distributed to public health nurses in seven areas of

child welfare clinics in the city of Oulu. Nurses were advised to distribute

questionnaires systematically to all those parents who came to the reception of the

clinic and had children under 2 years of age. Both mother and father had a

possibility to complete the questionnaire at home or at the clinic and return it

anonymously in a closed envelope to the nurse.

The material analyzed consisted of 116 questionnaires (45%). Quantitative

data were analyzed using SPSS for Windows version 12.0 (SPSS Inc., Chicago,

IL, USA) and MS Excel. Cross-tabulation and the χ2 test were used when follow-

up density and using a baby monitor to listen to the baby were compared as well

as when children who slept longer outdoors and those children who slept longer

indoors were compared with the number of siblings and the types of housing. The

one-sample t-test was used for testing the hypothesis. Non-responder (n = 10)

analysis was conducted for testing whether non-responder bias affected the results

(Kotaniemi et al. 2001). Data from those who responded to the questionnaire and

those who did not were compared using cross-tabulation, the χ2 test and the

Mann-Whitney test. Data of open questions were content-analyzed.

There was a need to understand profoundly the meaning of children sleeping

outdoors in winter as there existed conflicts between some viewpoints in the

results in Study I, such as parents’ opinions that there are no disadvantages to

letting the child sleep outdoors in winter, although parents also evaluated that

their child had had cold hands or feet after outdoor sleeping.

Finnish mothers who let their child sleep outdoors and who lived in Northern

Finland constituted the inclusion criteria for interviews (Study IV). Purposive

51

sampling with potential to provide rich data was used when cases with a wide

range of variation on the experiences of outdoor sleeping practice were selected

purposefully (Patton 1990, Giacomini & Cook 2000, Côté & Turgeon 2005, Polit

& Beck 2010); mothers living in the countryside and in cities in a large

geographic area in Northern Finland, mothers with different family sizes, and

mothers who regularly put their children out to sleep as well as mothers who did

not let their children sleep outdoors so often were selected for the interviews.

Snowball sampling was used, i.e. some mothers recruited other mothers who

conformed to the selection criteria (Parahoo 2006, Polit & Beck 2010). In

addition, public health nurses asked mothers to volunteer, and announcements of

the possibility to participate in the study were placed on notice boards at child

welfare clinics.

A qualitative design was adopted, and unstructured interviews were used to

collect the data. The location where the interview took place was selected by the

participants when mothers were interviewed once face-to-face at home or in the

researcher’s office between 2007 and 2010. The data were collected until

saturation was reached (Dey 1996, Parahoo 2006, Polit & Beck 2010). The

interviews were recorded, except for one mother whose interview was written

down. The average duration of the interviews was 36 min (range 20–61 min),

which constituted 254 transcribed A4 pages.

Inductive content analysis was used for the purpose of building up conceptual

categories (Hsieh & Shannon 2005, Elo & Kyngäs 2008). A meaning unit (a word,

part of a sentence, a sentence or a paragraph) which constituted a central meaning

was selected as the unit of analysis (Graneheim & Lundman 2004). Data were

reduced by coding, and comparisons were made for finding similarities and

differences between codings. These were organized into relevant sub-categories.

Generic categories were created through interpretation by grouping sub-categories

that belonged together, and by continuing the process of abstraction and

combining generic categories, the main category was formed and conceptualized.

(Dey 1996.)

4.3.2 Observation and physiological measurement of infants

Measuring infants’ skin temperatures and observing sleep durations gave a chance

to obtain information about the sleeping child in the winter environment.

Observational studies and defining the characteristics and risks of environments

of people’s everyday lives are needed for enhancing environmental health and

52

protection (Lebowitz et al. 2008, Barrett 2009). Measurements in this study were

as noninvasive as possible, and they did not affect the normal sleeping habits

when recordings were made in the natural settings of the families’ homes under

weather conditions and wrapping type chosen by the parents. Event sampling

included in structured observation was done when data were collected to

document specific events (Parahoo 2006, Polit & Beck 2010) of infants’ daytime

sleep outdoors and indoors. This study was a nonexperimental study where the

researcher did not intervene with the independent variable (Polit & Beck 2010).

Selection criteria included healthy outdoor-sleeping infants aged about 3

months (Studies II–III). At that age, infants’ sleep has developed so that well-

defined daytime naps can be specified (Parmelee et al. 1964) and the outdoor

sleeping practice in families was thought to already have developed (Study I).

The sampling was nonprobability convenience sampling (Polit & Beck 2010) as

the voluntary families were recruited through public health nurses in child welfare

clinics and using parents’ social networks and snowball sampling.

Normal skin temperature values in children are undetermined (Azaz et al.

1992, Svedberg et al. 2005); therefore Study II was designed to assess skin

temperatures during outdoor as well as indoor sleeping in the same infants. Study

II was conducted as a crossover study where subjects (n = 33) served as their own

controls (daytime sleep indoors and outdoors). Moreover, measurements of one

child were done only outdoors. Outdoor and indoor measurements were

performed at a time corresponding to daytime sleep, and depending on the

weather conditions, the parents decided whether the infants first slept outdoors or

indoors. Measurements were performed during weekdays due to the same rhythm

of the day, with the exception of measurements in two families, which were done

on weekends, as they had the same kind of rhythm during the week and on

weekends. The mean (SD) interval between measurements for each infant was 7

(5) days; the first test was done outdoors in 22 families, indoors in 11 families,

and only outdoors in 1 family.

Quantitative data were collected as objectively and accurately as possible

(Parahoo 2006) when in vivo measures were performed, i.e. measures performed

directly within or on living organisms (Polit & Beck 2010). Skin temperatures

were measured at 7 sites on skin areas on the forehead (T1), cheek (T2), chest (T3),

lower arm (T4), back of the hand (T5), shin (T6) and dorsal foot (T7) using

thermistor probes (Dräger skin temperature sensor, part number 2M21916,

2M21943, Drägerwerk Aktiengesellschaft, Germany). The probes were securely

attached to the infant’s skin with adhesive tape using thicker tape for insulation on

53

the forehead and cheek during outdoor sleep. The probes were always placed at

the same lefthand body side as skin temperatures have been shown to be

symmetrical on both sides of the body (Svedberg et al. 2005). A data-logger

(SmartReader 8; ACR Systems Inc., Vancouver, Canada) recorded temperatures at

one-minute intervals throughout the infant’s sleep. During outdoor sleep, the

recording started when the child was taken outdoors and during indoor sleep

when the child was laid in the cot. Recordings were discontinued when the child

woke up and was taken indoors.

The mean skin temperature (Tsk) was calculated by weighing the local skin

temperatures by representative areas according to the following equation

(Solomon 1985, Puhakka et al. 1994):

Tsk = 0.14 × T1 + 0.05 × T2 + 0.34 × T3 + 0.14 × T4 + 0.05 × T5 + 0.21 × T6 + 0.07 × T7

A structured observation data collection procedure was done: background

information, environmental circumstances, clothing information, the general

condition of the child and events during the child’s daytime sleep were written

down. The infants were closely monitored during sleep by the same experimenter

and the mothers, both to check security because of the probes and to take notes on

events during the infants’ naps. When the infant was settled, with eyes closed

sleep was defined as starting; the infant was defined as being awake when the

eyes were open and the infant was babbling, crying or moving. The duration of

sleep was observed and the precise time of sleep onset and the end of sleep

written down. Subjective temperature assessment was carried out by palpating the

infant’s hands and feet immediately after sleep and estimating if the hands and

feet were felt cool or cold or if the infant was sweaty. Photographs were taken of

the child and the environment for creating a possibility to go back and check the

observations and measurements procedures.

SPSS for Windows version 16.0 (SPSS Inc., Chicago, IL, USA) was used in

statistical analysis. In serial measurements, summary measures are analyzed in the

same way as in the original observations and raw data (Altman 1990, Matthews et

al. 1990), and the results are given as means, standard deviations and correlations

calculated by the Spearman correlation coefficient. The paired-samples t-test was

used to compare durations of sleep, ambient temperatures, Tsk between sleep onset

and end of sleep, and changes in Tsk for 33 infants. The rate of change of Tsk

(°C/min) was defined by calculating the difference between the mean Tsk value of

a 6-minute period from the end of sleep and a 6-minute period from the onset of

the infant’s peaceful sleep. The same 6-minute period at the end of sleep was used

54

for calculating central (T3) – peripheral (T7) skin temperature differences. The

Independent-Samples t-test was used to test the relationship with outdoor sleep

duration and going for a walk during outdoor sleep by mother as well as carryover

effect between treatments’ order (outdoor/indoor sleep) with outdoor sleep

duration. Results were considered significant at a level of p < 0.05.

4.3.3 Microclimate and clothing insulation measurements

Microclimate temperatures of the infants’ clothing (Study III) were recorded at

the same time as skin temperatures (Study II), and ambient air temperature, air

velocity, and humidity between clothing layers were recorded. Specific data were

collected about the type and amount of clothes, which were based on prevailing

weather conditions and experiences of the parents. For the evaluation of the

thermal insulation of the clothing of infants sleeping outdoors in the northern

winter connections between Study II and Study III were needed (Figure 4).

Fig. 4. Connections between Study II and Study III.

Study II

CHILD

Clothing information

Activity level

Tsk

ENVIRONMENT

Temperature

Air velocity

Study III

IREQGeneral

calculationsfor different

ambienttemperatures

THERMALMANIKINClothinginsulation

measurements

INSULATION OFOBSERVEDCLOTHING

INDIVIDUAL CALCULATIONSOF IREQ-VALUES

EVALUATION

55

During outdoor sleeping, microclimate temperatures were recorded inside the

middle layer (T8), inside the infant’s snowsuit (T9), inside the sleeping bag (T10),

10 cm from the infant’s face (T11), and 50 cm from the pram (Ta). During indoor

sleeping probes were inside the middle layer if used (T12), inside the covering

(T13), 10 cm from the infant’s face (T14) and 50 cm from the cot (Ta). The probes

(NTC DC95, type 22520HM, DIGI-KEY, Thief River Falls, MN, USA) were

placed on the left side on the infant’s chest and connected to a data-logger

(SmartReader 8; ACR Systems Inc., Vancouver, Canada), which was set to make

recordings at one-minute intervals. Air velocity was recorded 100 cm from the

pram by using an anemometer (Testo 491, Testoterm GmbH & Co., Lenzkirch,

Germany). Humidity (RH%) was recorded at five-minute intervals with a

miniature temperature and humidity recorder (OM-CP-MicroRHTemp, OMEGA,

USA) placed on the infant’s underclothing, on the infant’s abdomen during sleep

indoors (n = 24) and outdoors (n = 25).

An 8-segmented baby thermal manikin (Kyoto Electronics manufacturing Co.,

Ltd) was used for the calculation of clothing ensembles’ insulation. Thermal

manikins are used for analyzing thermal relationship between the human body

and its environment and in determination of thermal insulation of clothing

(Holmer 2004). The manikin was placed in a climatic chamber (The Research

Center for Human Environment Adaptation at the Faculty of Design, Kyushu

University, Fukuoka, Japan) with air temperature set at −10°C and relative

humidity at 50% for clothing ensembles No 3–9 and at +22°C for clothing

ensembles No 1–2 (see Appendix 1). The manikin was laid on 3 mattresses

(Appendix 1, Test No 1–5) or on one mattress with the pram (Appendix 1, Test

No 6–9) in supine position, which was how most infants slept while napping

outdoors. Segments of the manikin were heated to 33.0°C, and after reaching

steady state, the computer system recorded the temperatures of each segment and

supplied heating energy every minute over ten-minute periods.

The clothing insulation measurements with the manikin consisted of nine

ensembles (see Appendix 1), where No 1 represented a clothing ensemble worn

indoors, No 7 the least and No 8 the most clothing that an infant might wear

outdoors in winter. No 9 consisted only of clothes from the Maternity package

version 2008 (Kela 2009). Clothes were washed twice before measurements,

because especially in families with more than one child clothes had been washed,

and washing may decrease the thermal insulation due to reduced thickness (ISO

9920 2007).

56

Three measurements were made for each clothing ensemble, and insulation

values are the arithmetic mean of single test results. Clothing ensembles’ total

thermal insulation (It), i.e. thermal insulation from the body surface to the

environment including all clothing, enclosed air layers and boundary air layer was

calculated using the equation of parallel method (temperature gradient divided by

surface area averaged heat loss), because the manikin surface temperatures

remained uniform (ISO 15831 2004, ISO 9920 2007, Oliveira et al. 2008):

–T s a

c

I T T A

H

,

where It is total thermal insulation of the clothing ensemble and surface air layer

(clo), A is area of the manikin’s surface (m2), Ts is mean skin temperature of the

manikin (°C), Ta is air temperature (°C), and Hc is total heating power supplied to

the manikin (W).

The additional insulation provided by clothes compared to the nude manikin

is expressed as effective clothing insulation (Icle). The thermal insulation of the

clothing ensemble can be expressed as m2°C/W or in clo units (1 clo = 0.155

m2°C/W) (Gagge et al. 1941, ISO 9920 2007).

If the observed clothing ensemble was different from that measured by the

manikin, the nearest matching ensemble from the manikin measurements was

selected. The ensemble insulation was corrected by adding or reducing the

insulation of different items (ISO 9920 2007). The thermal insulation of different

clothing items was derived from the thermal insulation of clothing ensembles

measured with the manikin.

The mathematical model of the required clothing insulation (IREQneutral) (ISO

11079 2007) was used for analyzing whether or not the observed clothing

ensembles worn by outdoor sleeping infants (n = 34) provided insulation that was

sufficient to maintain thermal neutrality. Calculation of IREQ (ISO 11079 2007)

is based on general heat balance equation and can be calculated by using the

following equation:

sk clT TIREQ

R C

,

where Tsk is mean skin temperature (°C), Tcl is clothing surface temperature (°C),

R is radiative heat flow (W/m2), and C is convective heat flow (W/m2).

Calculations of clothing insulations (ISO 9920 2007) and IREQ (ISO 11079 2007)

have been developed from the viewpoint of the average adult, and to our

57

knowledge this is the first time when calculation of IREQ is used for estimation

of thermal insulation of infants’ clothing ensembles together with a pram. The

large outer surface area reduced the insulation (ISO 9920 2007). The insulation of

the pram and its greater surface area has been taken into account by calculating

the total insulation (It) and the effective clothing insulation (Icle) by using thermal

manikin measurements, which includes the reduced insulation effect of the

surface area (ISO 9920 2007). This represented an about 0.5 clo decline in

insulation of clothing ensembles with pram. The basic insulation (Icl), where the

effect of the surface area has been taken away, was calculated.

Individual IREQ (Icl) values of each outdoor sleeping infant were defined by

using the values of mean outdoor air temperature and air velocity measured

during each sleeping situation. The metabolic rate of sleeping infants in

thermoneutral conditions was estimated to be 50 W/m2 based on earlier studies:

28–55 W/m2 (Arkell et al. 2007), mean (SD) 45 (10) W/m2 (Hull et al. 1996a,

Hull et al. 1996b), and 53–60 W/m2 (Rising et al. 2003). For the estimation of

sufficient clothing insulation in use the difference between observed clothing

insulation and IREQ [observed clothing insulation (clo) – required clothing

insulation (clo)] was calculated.

General IREQ was calculated by using air velocity of 0.4 m/s, which was the

mean value during the outdoor sleeping situations of infants (n = 34), and relative

humidity of 85%, which was the mean value in Northern Finland from November

to March (Finnish Meteorological Institute 2009).

SPSS version 16.0 for Windows (SPSS Inc., Chicago, IL, USA) was used in

statistical analysis. Infants slept for a shorter time indoors than outdoors (Studies I,

II), and for that reason the most stabile moment was selected when comparing

mean temperatures at the point of 60 min (T8–10) outdoors with mean temperatures

at the point of 30 min (T13) indoors by using Paired-samples t-test. Comparisons

between observed (clothing in use) and predicted (IREQ) insulations of clothing

ensembles were calculated by using Paired-samples t-test as well. The Spearman

correlation coefficient was used for calculating correlations. Relationships

between cooling rate of Tsk and the difference between observed and required

insulations as well as between outdoor air temperature and the difference between

observed and required insulation were predicted by using Linear regression. The

effect of exposure time for cooling was assessed by calculating mean difference

between central (T3) and peripheral (T7) skin temperature in the course of time.

58

4.4 Ethical considerations

There are ethical considerations at every stage of the research process, from the

choice of topic to publication (Parahoo 2006). The choice of the research topic of

children sleeping outdoors in winter was based on the findings of previous

research among adults that cold exposure causes adverse health effects on humans

(Näyhä 2000, Rytkönen et al. 2005) as well as on lack of information as to

whether infants are exposed to cold environment during outdoor sleeping.

Physiological measurements of infants were needed due to their different

thermoregulation, stage of development and smaller size compared to adults, and

observations in the natural settings were conducted to evaluate the risk of cold

exposure of outdoor sleeping infants.

Observing children who might be exposed to risks in their environment can

create ethical dilemmas for the researcher (Resnik & Wing 2007, Resnik & Zeldin

2008, Resnik 2009). Observational studies in daily environment are an

appropriate scientific method of determining exposures such as cold exposure in

this study, when purposeful exposures and increased risk is not involved

(Lebowitz et al. 2008). Infants would have faced the same risks even if they had

not participated in the study (Resnik 2009). The same lowest outdoor air

temperatures in which parents let their children sleep outdoors were seen in the

findings of the questionnaire study (Study I) as when the skin temperature

measurements were done in Study II. We also knew that allowing children to

sleep outdoors in the winter is a common childcare practice (Tourula et al. 2008).

However, if the well-being of the participants is found to be at risk during the

conduct of the observational study, it should be stopped (The International

Society for environmental Epidemiology 2009, Resnik 2009). Skin temperatures

were controlled while the infants were sleeping outdoors, and the limits of lowest

skin temperatures were determined beforehand. Once we advised taking the child

indoors before it woke up. If considerable evidence for risks can be found

according to earlier studies, participants should be informed about those risks

(Resnik & Wing 2007, Resnik 2009). The parents were informed that the

childcare practice of children sleeping outdoors in winter had not been studied

earlier and thus we did not know whether children were exposed to cold during

outdoor sleeping. We discussed with parents that according to studies among

adults, cooling was found to cause adverse health effects.

In order to ensure the reliability of the findings, the collection of the data of

physiologic measurements was continued after winter 2007 to winter 2008.

59

According to analysis after the first winter when skin temperature measurements

were conducted in 16 infants it was estimated that sample size and the minimum

necessary number of participants had to be increased. However, there should be

as few children as possible recruited to studies to attain reliable findings (ETENE

2003). The calculation of power analysis for sample size was not performed,

because skin temperature levels of infants during outdoor sleeping were not

available due to lack of earlier studies (see Scheinin 2001, Uhari & Nieminen

2001).

This study was estimated to provide benefit both to the participants and to the

same age group (ETENE 2003, Medical Research Act No. 488/1999). The curves

of skin temperatures of all 7 skin sites and preliminary analysis were given to the

parents of participating infants after measurements, and advice about clothing and

temperature limits was given if needed. The findings of this study can be utilized

when updating guidelines on infants’ of outdoor sleeping.

Responding to the questionnaire (Study I) was based on voluntariness and

informed consent, where assumption of implied consent was used, i.e. returning

the questionnaire reflected voluntary consent to participate (Polit & Beck 2010).

Written and verbal information was provided and informed consent obtained from

the parent of each infant by having participants sign a consent form stating

voluntariness and willingness to participate (Studies II–III) and from all

interviewed mothers (Study IV). The ethical procedure of the study was approved

by the Ethical Committee of the Northern Ostrobothnia Hospital District (84/2006)

and the study plan was approved by the postgraduate research committee at the

Faculty of Medicine, University of Oulu. In those cases where public health

nurses asked voluntary participants in child welfare clinics, approval was given

by the chief of the health care unit. The privacy of participants was maintained

through possibility to answer the questionnaire anonymously (Study I).

Permissions for tape recording during interviews (Study IV) were requested, and

the tapes were transcribed without the names of the participants. The data from

physiological measurement of infants were also analyzed and the findings

reported without names. All the data of Studies I–IV were treated in confidence.

No monetary incentive for participation was provided in studies I–IV. Possibility

to contact the researcher as well as to withdraw from the study at any time was

brought out to the participants. The principles of research ethics were taken into

consideration during the research processes (Academy of Finland 2008, World

Medical Association 2008).

60

61

5 Results

There is fluctuation in children’s sleeping episodes from day to day and between

different families. The outdoor sleeping childcare practice binds juggling acts on

the part of the family on different levels. In general, a fit was found between

family – cultural outdoor sleeping childcare practice – Northern Finnish winter

environment, constituting a coherent whole. However, balance was not found

during some sleep episode causing an increase in adverse effects.

Different points of view and results on every level are gathered in the

evaluation model of outdoor sleeping episode (Figure 5). Evaluation on each level

shifts the pointer of goodness of fit either to the direction of beneficial or adverse

effects.

Detailed results are presented from level to level, starting from the

description of the environment to the skin temperature of the infants.

62

Fig

. 5. T

he

eva

luati

on

mo

de

l o

f o

utd

oo

r s

lee

pin

g e

pis

od

e.

63

5.1 Winter environment in Northern Finland

The quality of the northern winter environment. Mothers described the northern

environment as consisting of four distinct seasons, with typical features of winter:

lots of snow and freezing temperatures when the coldness of the weather was

increased due to wind (Study IV). The outdoor sleeping children were exposed to

many kinds of environments, from sunshine to heavy snowfall in the winter. The

temperature limits for allowing the child to sleep outdoors varied quite a lot from

family to family, the coldest being about −30°C. (Studies I–IV.) The best

temperature was evaluated to be about −6°C (ranging from +7 to −15°C), and the

largest group of parents answered that −5°C was the best temperature for having a

child sleep outdoors (Study I). Mean air velocity was 0.4 m/s; air velocity ranged

instantly from 0 to 9 m/s during the skin temperature measurements and mean

velocity from 0 to 2.23 m/s (Study II). When staying indoors, infants slept in cots

or prams (Studies II, IV), the mean (SD) room ambient air temperature (Ta)

ranging from 17.7 to 24.8°C [mean (SD) 22.1 (1.5)°C] and outdoors from −25.9

to 2.2°C [mean (SD) −5.9 (5.9)°C]. During the measurements in Study II, the

mean temperature difference between Ta outdoors and indoors was 27.9°C (95%

CI: 25.7 to 30.0°C, p < 0.001); the maximum difference was 47°C. The mean

temperature difference (T11–T14) was slighter near the infants’ face outdoors and

indoors: 19.7°C (95% CI: 18.0 to 21.4°C, p < 0.001).

In winter the days were short and darkness came early. The winter

environment was described as providing an ideal and favourable setting for

children to sleep calmly, because it was sleepy, silent and peaceful and there was

fresh and clean nature and pure air. Especially rural surroundings were considered

ideal for sleeping outdoors, with only natural sounds being heard:

In the winter environment there are no disturbing sounds. There was only the

sound of footfall as dry snow creaked under the soles of my shoes. (Mother,

Study IV.)

On the contrary, the harsh and changeable weather posed challenges to families.

The greenhouse effect caused different, shorter, “strange” winters that came later

than normal. The northern city environment was also described as sometimes

noisy and the air polluted. (Study IV.)

The countryside in Northern Finland was described to be safe, but the social

context of the downtown was considered insecure – however, less so than in

64

southern Finland. In general, Finland was described to be safer than some other

countries. (Study IV.)

Dimensions of the northern winter experiences. The natural northern winter

environment was highly valued and mothers were satisfied with their living place

expressing that they were “a people of the north”. The northern life-style was

described as being close to nature and mothers wished that their children would

learn the same respectful attitude towards nature that they had, and their aim was

to make outdoor activities an enjoyable part of the life-style of their children

throughout their lives. The relationship between the child and the natural

environment got a start by sleeping outdoors, and this connection was gradually

reinforced through engaging in many kinds of outdoor activities in the expanding

milieu. The winter environment was seen as an affordance for the child to sleep

outdoors and produced many affordances for older siblings. Families with little

children spent much of their time outdoors playing and engaged in different kinds

of activities:

We have a one-family house and we have outbuildings there and a slide just

there in our own yard; we have built it up after the plough truck drove from

there. What we usually do when we go out, we dig snow with a spade,

because we dig a path to the sauna and warehouse. And then we make snow

cakes, glide and go to the grocery store by kick sled. It takes about 15

minutes when for example the younger child is in a baby sling and the older

is sitting on the kick sled or uses the kick sled herself. We walk a lot. (Mother,

Study IV.)

Negative attitudes were also mentioned when the winter environment was felt to

limit and make going outdoors cumbersome if a lot of snow had fallen. The cold

winter also meant higher costs to families; for example appropriate clothes and

prams cost a lot, putting a strain on families’ economic resources.

5.2 Cultural knowledge-building

Families have generated shared knowledge about children sleeping outdoors in

winter during some generations. Social knowledge building involved comparisons

between experiences and opinions with grandmothers, friends, other mothers, and

cultures as well. Practical details, temperature limits, duration of sleep, possible

correlations with outdoor sleeping and falling ill have been discussed. During

they walks mothers made observations on how other mothers managed and had

65

dressed their children. The mothers had noticed how differently people can see

the cold winter outdoor environment when they had been abroad or met families

who had moved to Finland. Place rules for behavior were different in different

cultures and the outdoor sleeping practice had caused wonder. For example a

mother from Brazil had said: “What on earth? People will freeze here!” while

Finnish woman who had moved to the USA had realized that no children slept

outdoors there. It was not easy to continue with outdoor sleeping childcare

practice then, for example due to lack of walkways and appropriate prams and

winter clothing. (Study IV.)

Culturally bound custom. Having children sleep outdoors is self-evident

(Studies I, IV) and common in the city of Oulu (95%) (Study I). Some of those

who did not take their child to sleep outdoors thought that this practice was of no

use and did not want to adopt it as a habit, or it was prevented by someone

smoking on the next balcony (Study I). Usually the mothers expressed that it was

natural to continue with the outdoor sleeping practice as it had been used by

earlier generations, e.g. one mother described how they had let their children

sleep outdoors at least during three generations since a Finnish pediatrician, Arvo

Ylppö, had recommended it. The mothers described old family photos showing

that having a baby sleep outdoors had been a moment worth taking a picture of in

those days. (Study IV.) Parents’ experiences were mainly positive (Study I) and

the interviewed mothers were going to recommend the outdoor sleeping childcare

practice to their children and friends as well (Study IV).

Outdoor sleeping as a norm. Guidelines, advice and encouragement about

having children sleep outdoors were given to mothers from different sources;

grandparents were the biggest group (39%) giving lots of advice, and a great

number of guidelines were also received from friends (33%) and from public

health nurses (28%) in child welfare clinics, which held an authoritative position,

especially from the point of view of first-time mothers. An important source of

support came from female family members and friends. Guidelines were also

found in books and magazines. (Studies I, IV.) Directions on how to dress the

baby were found in the Finnish maternity package as it contained a winter

clothing ensemble and sleeping bag. Some mothers were not able to mention a

single source from where they have received advice, as it had always been so

generally encouraged (Study IV); only 3% of parents had been advised not to take

the child out to sleep in the winter (Study I). The childcare practice of having

children sleep outdoors in the winter has gradually become a commonly accepted

66

collective, a type of behavior that is sometimes felt to be compulsory. The outdoor

sleeping childcare practice has been described as a myth (Study IV).

5.3 Family well-being

Outdoor sleeping episode as one building block of everyday life. Outdoor sleeping

usually took place once a day (52%) (range 3 times a month to twice a day)

(Study I). The episode consisted of three phases: preparing, getting to sleep and

waking up. Mothers fed their babies, looked for appropriate clothing, dressed

their babies carefully and laid them peacefully down in a pram. (Study IV.)

Infants usually slept in prams on the balcony, veranda or in the garden (Studies I–

IV). The babies who cried needed to be swayed to sleep and the mothers went for

a walk with them. The families did their outdoor activities while the babies took

their daytime naps. Sometimes the mothers stayed indoors with the rest of the

family while the baby was sleeping outdoors alone (Studies I–IV). Some children

woke up peacefully babbling, with some older children calling for mother from

the pram outdoors, whereas others cried (Study IV).

The mothers had “season babies”: winter babies had to wait about two weeks

until they were allowed to sleep outdoors, as opposed to spring babies who were

let to sleep outdoors at once (Study IV). Outdoor sleeping was usually

commenced when the child was two weeks old (range 3 days to 7 months) (Study

I). Some children expressed their wish to sleep outdoors, even saying it out loud,

telling the mother how the blankets should be placed. Babies learned to sleep

longer periods outdoors in prams so well that some mothers encountered

problems when they tried to have the babies sleep indoors, and the mothers had to

trick the babies into believing that they were outdoors by dressing them in

outdoor clothes and putting them in the pram. (Study IV.) The age of the child

when the outdoor sleeping practice was stopped varied between families (Studies

I, IV), the oldest children being about 3 years then (Study I). When the child grew

taller and the prams got too tight or the child started to move more in the pram

were reasons for ending the practice (Study IV).

Fluency of everyday life. Having children sleep outdoors was a daily routine

in the families creating rhythm for the day, and this way regularity and fluency of

everyday life was strengthened. Mothers also described how they needed to get

outdoors; they got a possibility to take care of their social relationships when

allowing the baby to sleep outdoors and go for a walk with the child, and at the

same time they improved their fitness and shed weight. It helped to combine

67

different outdoor activities of other members of the family as well. The outdoor

sleeping childcare practice was an important factor enhancing the family’s well-

being. (Study IV.)

Mother’s personal knowledge-building. Mothers built their personal

knowledge of outdoor sleeping as their experience increased. During pregnancy

they already intended to let their child sleep outdoors, as it represented one aspect

of healthy childcare and was fraught with big expectations, similarly to

breastfeeding. Especially young mothers followed guidelines and advice they had

received to the letter, as well as learning the practice through experience, by

trying and discovering their own ways of doing it. They were motivated to do

their best for their children and to fulfill their needs, striving to be good mothers.

Mothers were sometimes very resilient when trying to get their babies to sleep

outdoors every day by pushing prams in the snow while pulling a sibling in a

sledge and often also walking the family dog on a leash. There were experiences

of a sense of being forced to do outdoor activities against one’s own will. (Study

IV.)

Some of the mothers wanted to use their common sense and intuition and

make independent decisions, for example when estimating when it was too cold

for sleeping outdoors. They explained how they did not want to be given so much

advice and how the everyday life of the family was not planned so strictly in

advance. Doubts concerning the necessity of this practice also came up. (Study

IV.)

The gamut of feelings fluctuated from “nothing special” to “very emotional”

and from positive to negative. Confidence in own skills, fluency of everyday life,

and success in attaining goals were positive feelings evoked by the practice,

whereas negative feelings consisted of uncertainty of one’s own ability to take

care of the baby correctly. When the mother was not able to put her baby outdoors

to sleep for different reasons, feelings of failure and guilt were experienced as

they felt that they failed to attain the goals of healthy childcare. Feelings of being

“bad mothers” and lazy were experienced. From time to time mothers had to give

up after trying hard, and they were dissatisfied when their idea of the baby

sleeping peacefully outdoors did not come true. The outdoor sleeping practice

was sometimes quite exhausting and burdensome; the baby had to be dressed in

so many articles of clothing and the mothers feared for their babies’ safety and

were on the alert for the many risks that might occur during outdoor sleeping that

it would have been much easier if the baby had slept indoors. This part of the day

68

and stage of life was very busy, especially in families with many children, and the

mothers with children with sleeping problems had a hard time, getting very tired.

The relationship between the mother and the baby fluctuated from unity to

separate. Mutual feelings and identification with the child were experienced by

mothers; for example when the child slept well and everything was all right, the

mother was also satisfied and happy; likewise, when mothers felt invigorated

during a walk, they assumed it as having the same effect on the baby. Outdoor

sleeping was described as a shared good experience. The relationship was

separate when mothers left their babies to sleep alone in the pram outdoors while

being indoors themselves. On the other hand, the distance was not described to be

a problem, as the distance was shortened by placing the baby within sensory

distance. During this daily separation when the baby was sleeping outdoors,

mothers had a moment of their own; they had a change to do some housework or

take a brief respite, read, rest and have flow experiences. During this time the

baby’s siblings also got more attention from their mothers. (Study IV.)

Safety. Many parents (88%) had not encountered any potentially dangerous

situations related to sleeping a child outdoors (Study I); however, mothers were

conscious of potential risks and had to take notice of many security perspectives

(Study IV). Cold environment could cause general, facial or bronchial cooling or

cooling of the extremities as well as frostbites (Study IV), and clothing, such as

gloves and hat staying in place and generally appropriate clothing in view of

weather, was observed by the mothers (Study I). Some mothers connected cooling

with the common cold. On the other hand, sweatiness of the baby caused by

overdressing was a risk which was sometimes described as being more common.

The baby’s activity also caused dangerous situations, as one mother described

how her baby had fallen to the ground from the pram. An older child could have

climbed down from the pram and walked off somewhere. Mothers were conscious

of the possibilities of social problems, such as kidnapping. (Study IV.) Animals

(cats, small birds, squirrels, mice and rats) in the immediate vicinity were named

as a risk factor (Studies I, IV), and there was even a risk that the pram might be

knocked down by the family’s pony (Study IV). Problems with well-being

technology had been encountered, as in some situations baby monitoring had been

broken off while the child was sleeping outdoors (Studies I, IV).

Protection against risk factors. It was not always possible to let children

sleep outdoors due to many reasons related to the child, the mother or the

environment; child’s illness, such as fever (97%) or otitis (85%) was according to

most of the parents an obstacle to taking the child outdoors, but a mild sniffle

69

(36%) or cough (38%) was not (Studies I, IV). Mother’s lack of know-how was

named as one obstacle. Environmental preventive factors which prevented

sleeping outdoors were poor air quality, noise from the surroundings, and bad

weather conditions.

Security and the physical factors of the environment as well as practical

perspectives affected mothers’ choice of location for having their child sleep

outdoors. The wind and which way it was blowing and where the sun was shining

were observed by the mothers, trying to find a sheltered, peaceful spot. Children

usually slept under windows, in the same familiar and constant prams, but if it

was difficult to get somewhere by using prams, also in sledges and wheelbarrows.

One mother told how their baby was laid in a basket hanging from the branch of a

spruce. (Study IV.)

The outdoor sleeping practice required more frequent observing than indoor

sleeping. When mothers were indoors they watched the prams through the

window and usually also used baby monitors. Mothers went outside to check that

everything was fine every 15 minutes (58%) or every half an hour (40%) in those

families who used a baby monitors. The sleeping child was frequently observed;

the frequency of going outside to observe the sleeping child was reduced by using

a baby-monitor. The child’s breathing, babble, moving and the amount and quality

of sleep were noted. The child’s temperature was evaluated by touching the

child’s skin from the neck or using a thermometer inside the pram. During the

child’s sleep also wind, the direction of the wind, rain, sunshine, changes in

weather and the climate as a whole were kept watched by the parents. (Study I,

IV.)

Mothers protected the children against harmful effects; first of all came cold

protection and using layered winter clothing (Studies I–IV).

5.4 Winter clothing of outdoor sleeping children

Mothers learned to know their babies, all of whom were unique individuals,

noticing how some children needed more clothes than others, for example one

child with Down’s syndrome reacted differently to cold. An attempt was made to

regulate the amount and quality of babies’ clothing ensembles and coverings

according to weather conditions. This was easy in the fall and spring, but became

challenging and difficult in the variable weather conditions in the wintertime

(Study IV), as was confirmed when clothing insulations in use (n = 34) were not

found to correlate with ambient air temperature (see Figure 1 in Publication III).

70

On the contrary, according to questionnaire (Study I), clothing insulation was

seen to be higher in colder conditions, and some mothers described that they had

a special clothing solution when it was colder than −20°C. Mothers took into

account the effect of the wind by adding extra covers on the pram, and some

mothers also limited the duration of the child’s sleeping time in cold weather.

(Study IV.)

The children were clad in layered clothing (Studies I–IV). Outdoor sleeping

infants’ (n = 34) mean (SD) clothing insulation (Icle) was estimated to be 5.54

(0.52) clo (range 4.35 to 6.47 clo) (Study III). Clothes and beddings did not vary

much indoors, where infants were usually clad in a bodysuit, disposable nappy,

footed leggings (sometimes tights, or leggings with socks or a romper suit) and

covers (blanket and duvet cover or sleeping bag). The same kind of underwear

was worn with the outdoor clothing ensembles. The middle layer had greater

variability in amount and quality, sometimes consisting of handmade woolens.

(Studies I, III.) According to the interviews, grandmothers knitted woolens for

their grandchildren and underwent the process of becoming grandmothers.

Clothing tradition was passed on from earlier generations and at the same time,

giving handmade pieces of clothing was a positive sign for outdoor sleeping.

(Study IV.) The middle layer also consisted of a balaclava hat, socks (usually

woolen, handmade), mittens (cotton or woolen), shirt and pants / overall (cotton,

fleece or woolen). Outer garments consisted of a hat, snowsuit with hood and

insulated mittens and booties. Sleeping bags were usually those included in the

maternity package (62%), but sometimes a thicker padded winter footmuff was

used. Some infants slept on a sheepskin. In nearly all cases (82%) the hood of the

pram was covered with gauze, net or cloth when using different kinds of pram

models. (Study III.)

Layered clothes, sleeping bags, other covers and the pram formed something

like swaddling clothes, restraining infants’ movements. When infants took their

daytime naps indoors, they slept under a blanket in cots or prams. The outdoor

used clothing ensembles’ (see Appendix 1, measurement no. 6–9) total thermal

insulation (It) with the pram ranged from 5.67 to 8.07 clo. The pram increased the

insulation of the clothed manikin by 1.44 clo / 0.22 m2°CW−1. The thermal

insulation of the clothing ensemble was divided so that underwear accounted for

10%, middle layer for 16%, outerwear for 35%, covers for 13% and the pram for

26% of the insulation. (Study III.)

The cold ambient air temperature came in close contact with the outdoor

sleeping child. When the child had slept outdoors for 60 min the mean

71

temperature inside the middle layer was 1.6°C (95% CI: 0.4 to 2.9°C, p = 0.014)

warmer than inside the blankets when the child had slept indoors for 30 min,

whereas the mean temperature inside the snowsuit was 3.5°C (95% CI: 5.6 to

1.5°C, p = 0.002) colder and mean temperature inside the sleeping bag 18.2°C

(95% CI: 20.3 to 16.2°C, p < 0.001) colder outdoors than indoors inside the

blankets. The temperature inside the middle layer decreased when cold ambient

air temperature cooled it down (rs = 0.442, p = 0.011), which led to a decrease

(rs = 0.533, p = 0.002) in Tsk. The observed and required thermal insulation of

clothing was equal at about −5°C. An increased difference between observed and

required clothing insulation was found when Ta decreased below −5°C, meaning

that the deficit of clothing insulation increased in colder ambient air temperatures.

On the contrary, overdressing existed when Ta was higher than −5°C (rs = 0.739,

p < 0.001, see Figure 2, Publication III), supporting hypothesis number 3a. When

the difference between observed and required clothing insulation increased the

cooling rate of Tsk increased linearly (rs = 0.605, p < 0.001, see Figure 3,

Publication III), supporting hypothesis number 3b. When the difference between

observed and required clothing insulation increased the infants also slept for a

shorter time (rs = 0.524, p = 0.001).

IREQ calculation (ISO 11079, 2007) shows the required clothing insulation

in different ambient air temperatures when infant’s metabolic rate is 50 W/m2

during sleep (Figure 6).

Fig. 6. IREQ-values have been calculated by using air velocity of 0.4 m/s, which was

the mean value during the outdoor sleeping of infants (n = 34). Relative humidity of 85%

was used as it represented the mean value in Northern Finland from November to

March (FMI 2009).

0

1

2

3

4

5

6

7

8

9

10

11

-34 -32 -30 -28 -26 -24 -22 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0 2

IRE

Q (

clo)

Temperature (°C)

72

When the insulation is less than IREQneutral the infant cannot maintain thermal

equilibrium without limiting outdoor sleeping time (ISO 11079 2007). For

example, when the infant is dressed in a clothing ensemble with about 5clo

insulation and laid in pram, the infant is allowed to sleep at −1°C outdoors

without time limits from the viewpoint of thermal equilibrium, but is also allowed

to stay outdoors when it is colder than −1°C for a shorter time. Maximum amount

of clothes gave appropriate insulation in ambient temperature of about −17°C

(Table 3.)

Table 4. Examples of required clothing ensembles in different temperatures

(Clo/m2°CW−1, °C).

Clothing ensembles Icle

Clo/m2°CW−1

Temperature limits

(°C)

Bodysuit, disposable nappy, footed leggings, mittens, socks,

balaclava hat, woolen hat, snowsuit, sleeping bag, pram

5.01/0.78 −1

Bodysuit, disposable nappy, footed leggings, playsuit, mittens,

socks, overall with wadding, balaclava hat, insulated mittens,

insulated booties, insulated hat, snowsuit, sleeping bag, pram

5.40/0.84 −4

Bodysuit, disposable nappy, footed leggings, mittens, woolen

socks, woolen cardigan and pants, balaclava hat, insulated

booties, woolen hat, snowsuit, sleeping bag, pram

5.60/0.87 −5

*Bodysuit, disposable nappy, footed leggings, mittens, woolen

socks, woolen cardigan and pants, balaclava hat, insulated

booties, woolen hat, snowsuit, padded winter footmuff,

sheepskin, pram

6.44/1.00 −10

*Bodysuit, disposable nappy, footed leggings, mittens, woolen

socks, playsuit (shirt and pants), woolen cardigan and pants,

balaclava hat, insulated booties, woolen hat, snowsuit, padded

winter footmuff, sheepskin, pram

6.86/1.07 −13

Bodysuit, disposable nappy, footed leggings, mittens, socks,

woolen socks, woolen mittens, playsuit (shirt and pants),

woolen cardigan and pants, overall with wadding, balaclava hat,

insulated booties, insulated mittens, insulated hat, snowsuit,

padded winter footmuff, sheepskin, pram

7.41/1.15 −17

* The thermal insulation of clothing ensemble is derived from the thermal manikin measurements, but not

measured directly by using the thermal manikin.

73

The average humidity (RH%) between clothing layers was 35.3% (range 22.6 to

64.5%) during outdoor sleeping, whereas during indoor sleeping it was 32.6%

(range 21.0 to 62.9%). Humidity was on average 40% at sleep onset, and

individual variations were found in the humidity trends; in general there was a

decreasing trend, but in some cases (n = 4) humidity increased during outdoor

sleeping. There was a clear association with maximum Tsk and humidity

(rs = 0.747, p ≤ 0.001) during outdoor sleeping, but this was not found indoors

(rs = 0.107, p = 0.619). Mean humidity was > 30 RH% when mean Tsk

was > 32.5°C (Figure 7). The biggest correlation was seen between mean

temperature of cheek and humidity (rs = 0.587, p = 0.002) when different skin

sites and humidity were compared. Mean humidity correlated with the

temperature of middle layer (rs = 0.471, p = 0.023), whereas correlation was not

noticed with clothing insulations (rs = 0.088, p = 0.677) or outdoor temperature

(rs = 0.102, p = 0.627).

Fig. 7. The correlation between mean relative humidity (RH%) and mean Tsk.

30 31 32 33 34 35

20

30

40

50

60

70

RH

%

Tsk (°C)

rs = 0.566

p = 0.003

74

5.5 Well-being of the children

Mothers described the surroundings of their child sleeping outdoors in the pram to

be a closed and safe nest with limited stimuli. Babies were bundled up and the

prams were veiled so that they could not see anything but the pattern on the hood

of the pram. The microclimate temperature and the motion when the wind rippled

the pram or the mother moved it created haptic stimulations to the child. At the

same time, the movements of the child were restricted by clothing and sleeping

bags as if they were swaddled. (Study IV.)

It was thought to be important for the child’s development to be outdoors in

nature. The children’s environmental health consisted of the beneficial health

effects of cool, fresh, humid and clean air as well as the sun shining in the later

stages of winter. (Study IV.) Some parents (29%) and interviewed mothers saw

outdoor sleeping as toughening the child to the harsh climate (Studies I, IV), and

fresh air was thought by most of the parents (94%) to be healthy for the outdoor

sleeping child. The better quality of sleep and being outdoors was thought to

enhance the child’s appetite (Studies I, IV), as well as growth and learning, and

have effects on mental development and better mood (Study IV). According to

parents (66%), children were more active after outdoor sleeping. Parents (88%)

evaluated that the child clearly enjoyed sleeping outdoors. (Study I.) The baby’s

mental security was promoted by foreseeable and familiar routines and regular

rhythm of everyday life. Some interviewed mothers had experiences of children

having fewer infections and illnesses when they had slept outdoors (Study IV);

however, most parents (65%) were not able to say whether their child might

remain healthier because of outdoor sleeping (Study I). The interviewed mothers

had a strong belief that outdoor sleeping promoted health of the baby; it was one

part of the wholeness of a healthy way of life, and the good of the child was the

basis for this childcare practice (Study IV).

5.5.1 Children’s sleep

Infants usually slept in a supine position both outdoors (74%) and indoors (55%).

Prone sleeping did not exist. (Study II.) The mothers had noticed that sleeping

outdoors improved the quality of sleep of their child, making it fall asleep quickly

and sleep soundly and longer, without interruptions (Study IV). Children took

significantly longer naps outdoors compared with naps taken indoors according to

both the questionnaire study (mean difference 34 min, 95% CI: 21–47 min,

75

p < 0.001) (Study I) and the observational study (mean difference 92 min, 95% CI:

74–110 min, p < 0.001) (Study II) supporting hypothesis number 2a (Figure 8).

Fig. 8. Outdoor sleeping durations in Study I (n = 106) and in Study II (n = 33).

The longer the baby slept indoors the longer he/she also slept outdoors (rs = 0.405,

p = 0.019) (Study II). The number of children in the families had an effect on the

difference in sleeping durations; according to the questionnaire, most of the

children (57%) in the group that slept longer outdoors had siblings, while most of

the children (74%) in the group that slept longer indoors were the family’s only

child (p = 0.05). Children slept longer outdoors than indoors in all types of

housing (p = 0.004). (Study I.) No significant differences between outdoor sleep

durations were found, whether the mothers went for a walk or not (p = 0.297)

(Study II).

Some external factors, such as noise from the surroundings or physiological

factors of the child, e.g. sweatiness or coldness were described as causing

76

awakening. Long duration of sleep was a sign of thermoneutrality, while shorter

and discontinuous sleep indicated coldness, according to some interviewed

mothers (Study IV):

If they felt cold, they woke up. Of course this could sometimes happen.

(Mother, Study IV.)

This was also noticed in the skin temperature measurements as infants reacted to

the increased cooling rate of Tsk by waking up; the cooling rate of Tsk had a

significant correlation with outdoor sleeping duration (rs = 0.611, p < 0.001) (See

Figure 3, Publication II). Infants were especially sensitive even to a slow cooling

rate of the chest (Figure 9). A slight correlation (rs = 0.352, p = 0.041) could be

seen between outdoor ambient air temperature and sleeping duration, but no

correlation (rs = −0.168, p = 0.351) was found between room temperature and

duration of sleep. (Study II.)

Fig. 9. The correlation between the cooling rate of chest (°C/min) and outdoor

sleeping duration (min).

50

100

150

200

250

300

Out

door

sle

epin

g du

rati

on (

min

)

Cooling rate of chest (°C/min)

rs = 0.658

p < 0.001

-0.020 -0.015 -0.010 -0.005 0.000 0.005

77

5.5.2 Children’s skin temperatures

Mean Tsk of all measurements in Study II decreased during outdoor sleeping and

increased during indoor sleeping. At the beginning of the recordings, higher level

in mean Tsk was seen outdoors compared to indoors due to clothing. (See Figure 2,

Publication II.) Tsk was significantly lower at the end of outdoor sleep compared

with indoor sleep (mean difference 1.23°C, 95% CI: 0.72–1.74, p < 0.001). The

mean difference of the rate of change of Tsk between outdoors and indoors was

0.025°C/min (95% CI: 0.018 to 0.033°C/min, p < 0.001) (Figure 10). During

outdoor sleeping the mean cooling rate varied at different skin sites, being fastest

in the cheek (−0.049°C/min) and slowest in the chest (−0.007°C/min). In the

extremities, the cooling rate was highest in the distal parts (−0.02°C/min). (Study

II.)

Fig. 10. The rate of change (°C/min) of Tsk indoors and outdoors.

Outdoor ambient air temperature had a clear effect on the cooling rate of Tsk

(rs = 0.628, p < 0.001) (See Figure 1, Publication II). Moreover, the difference

78

between outdoor air temperature and temperature near the infants’ face (T11)

decreased with increasing air velocity, (rs = −0.491, p = 0.004). At the same time,

the T11 affected the mean temperature of the cheek (rs = 0.524, p = 0.001). Air

velocity also slightly affected the cooling rate of the dorsal foot (rs = 0.384,

p = 0.028).

Skin temperatures of all measured sites were lower at the end of outdoor

sleep compared with indoor sleep, being significantly lower in the cheek (mean

difference 8.54°C, 95% CI: 6.73–10.36°C, p < 0.001), lower arm (mean

difference 1.46°C, 95% CI: 0.67–2.25°C, p = 0.001), back of the hand (mean

difference 2.12°C, 95% CI: 0.89–3.35°C, p = 0.001), shin (mean difference

0.79°C, 95% CI: 0.22–1.37°C, p = 0.009), and dorsal foot (mean difference

2.57°C, 95% CI: 1.41–3.73, p < 0.001), supporting in this respect hypothesis

number 2b. (Study II.)

According to the subjective reports of the parents in the questionnaire study,

children had cold fingers in 3% of the cases at 0°C and 25% at −15°C or colder,

but cold toes were observed less frequently, in 3% and 16% of the cases,

respectively (Study I). Frequencies of cool hands were recorded after outdoor

sleeping in Study II: 9% had cool (27.0–27.6°C) and another 9% had cold (21.4–

22.7°C) hands. Cool (26.3–28.9°C) feet were recorded in 15% and cold (21.2–

23.7°C) feet in 9% of the infants. The coldest area was the cheek with 47 % of the

infants having cool (20.1–24.8°C) and 18% cold (12.2–18.4°C) cheeks. (Study II.)

A white area on the cheek was uncommon; it was seen in none at 0°C and in 4%

at −15°C or colder (Study I). Frostbite of cheek came up in the interviews with

the mothers:

Once my own child got a frostbite on his cheek when the weather was frosty.

He had moved in the pram so that his cheek was exposed and dribble-soaked.

The cheek was frostbitten in a small area; it was a kind of bluish area in the

cheek that lasted the whole winter. (Mother, Study IV.)

Frostbites of other parts of the body or hypothermia did not come up in any data

in this study.

Increased differences between chest and peripheral (dorsal foot) skin

temperatures were seen at the end of outdoor sleep, suggesting the effect of

vasoconstriction. The mean (SD) temperature difference between chest and dorsal

foot was 3.7 (3.2), ranging from −0.3 to 12.4°C. Smaller differences were seen

between the lower arm and back of the hand and between the shin and dorsal foot.

The colder the outdoor air temperature, the bigger the maximal differences

79

between the lower arm and back of the hand (rs = −0.454, p = 0.007) as well as

between the shin and dorsal foot (rs = −0.387, p = 0.024). Differences were found

in skin temperatures’ cooling between different skin sites: the mean (SD)

difference of cooling between the lower arm and back of the hand was −0.9

(2.0)°C (95% CI: −1.6 to −0.2°C, p = 0.012), between the shin and dorsal foot

−1.8 (2.0)°C (95% CI: −2.5 to −1.1°C, p < 0.001), and between the chest and

dorsal foot −1.8 (2.5)°C (95% CI: −2.7 to −0.9°C, p < 0.001). (Study II.) The

mean difference between central and peripheral skin temperature exceeded the

start difference (2°C) when infants (n = 10) had been outdoors about 200 min or

longer (Figure 11).

Fig. 11. Central-peripheral temperature difference (Td) over the course of time. All

results for subjects were summarized in composite graphs. Sample size decreases

over the course of time.

-2

-1

0

1

2

3

4

5

6

7

8

9

0 30 60 90 120 150 180 210 240 270 300

Skin

tem

pera

ture

diff

eren

ces

(°C

)

Time (min)

lower arm - back of the hand

shin - dorsal foot

chest - dorsal foot

80

On the other hand, also sweatiness of the children was observed during outdoor

sleeping. According to the questionnaire study, almost half of the children had

sweaty necks at 0°C, with decreasing prevalence in colder temperatures (Study I),

and according to Study II, 32% of the infants were estimated to be warm or

sweaty, compared to none after indoor sleeping.

81

6 Discussion

The use of mixed methods approach elicited new, different and complementary

findings between qualitative and quantitative methods. The qualitative part of this

study contributed to connecting the findings of physiological measurements to the

broader context, with all parts and levels of the study constituting a

comprehensive view. For example, if only skin temperature measurements had

been done, the emphasis would have been more on the negative effects, ignoring

the promotion of family well-being. A combination of quantitative and qualitative

research provides a better understanding of the research problem than either

approach by itself (Creswell 2005). On the other hand, if only one level of the

phenomenon had been studied, there would have been a possibility to study it

more profoundly. The quality of mixed methods research could be considered by

examining whether the chosen methods are correct in terms of providing answers

to the research questions, whether different parts of the study are implemented

and data analyzed appropriately as well as how smoothly different parts are

connected to the whole (Tashakkori & Teddlie 2008).

The similarities in the qualitative and quantitative parts helped to confirm the

data. For example, parents estimated that their child slept longer outdoors than

indoors and reacted to the cold by waking up earlier (Study I, IV), findings which

were confirmed in the observational study (Study II). Parents also evaluated in the

questionnaire study (Study I) that the best temperature for letting their child sleep

outdoors was about −5°C, which was confirmed by the clothing insulation study

(Study III), showing that parents usually clothed their child appropriately at about

−5°C; the maternity package also gave insulation at −5°C. The mixed methods

approach strengthens the validity of findings by obtaining similar results via each

of the methods employed (Greene 2005).

In the contemplation of the rigor of the study both factors related to

quantitative (validity, reliability) and qualitative study (credibility, dependability,

confirmability and transferability) should be taken into account (Tashakkori &

Teddlie 2008).

6.1 Validity and reliability of the quantitative studies

Validity refers to the degree to which inferences are accurate and well-founded as

well as the degree to which an instrument measures what it is intended to measure.

Content validity concerns the degree to which the items in an instrument

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adequately represent the completeness of the content of the concept being

measured. (Polit & Beck 2010.) Content validity was taken into account when the

questionnaire (Study I) aimed to provide a comprehensive view of children

sleeping outdoors in winter was compiled by first interviewing mothers and then

using a panel of experts and pilot test. However, the larger interview study (Study

IV) and skin temperature (Study II) and clothing insulation (Study III)

measurements showed that the questionnaire could be more comprehensive and

thus needs to be improved for additional researches.

In Study II, the validity of measurements of Tsk was increased when Tsk was

measured at seven skin sites instead of two, such as the cheek and abdomen, as is

usually the case (Telliez et al. 1997, Bach et al. 2000a, Bach et al. 2001, Telliez et

al. 2004). Core temperature measurements could have provided more specific

information about thermoneutrality, but they would have reduced volunteers’

willingness to participate in the study (Baddock et al. 2004), and above all the

possibility of risk for adverse effects to the infants could have increased.

Actigraphic sleep measures, which have been considered a reliable and

accurate data collection method in children, could have been used for the data

collection of infants’ sleep durations (Tikotzky & Sadeh 2001, Asaka & Takada

2011). However, when actigraphy and parental daily sleep logs have been

compared, similar data for sleep duration have been obtained (Sadeh 1996,

Tikotzky & Sadeh 2001), and an attempt was made to make the measurements in

Study II as non-invasive as possible. A limitation of the study is that an

observational design was used in natural settings instead of an experimental

design with more constant conditions; furthermore, more detailed study of sleep

stages and total diurnal sleep duration was missing. At the same time, data

collections in natural settings strengthen the study, because the sleeping

environment of the infants was familiar and did not cause any additional stimulus.

Before the use of the probes and data loggers in Study II, accuracy was tested

by placing the probes in water at known temperature. The system of using

equipment was tested in one child before primary measurements. These kinds of

probes and data loggers have been used for a long time for the purpose of

measuring thermal conditions of the human body and there have not been any

validity problems. Physiological measurements are objective, relatively accurate

and precise, providing valid measures of targeted variables (Polit & Beck 2010).

Selection bias may pose a threat to internal validity (Polit & Beck 2010).

Nonprobability sampling was used in quantitative studies (Studies I – III). This

increases the possibility of sampling bias (Polit & Beck 2010). An attempt was

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made to evaluate the possibility of bias by using nonresponding analysis in Study

I. It gave the assumption that there was no essential bias. In Study II, the lack of

nonprobability sampling might have caused a bias in which a disproportional

amount of families taking good care of their babies and infants without sleep

problems took part. Those mothers whose infants were used to sleeping outdoors

for a long time might have chosen to participate. This can be seen when looking

at the findings on sleeping duration (Figure 6), as much longer outdoor sleeping

durations where seen in the Study II than in Study I. On the other hand, infants

were about three month of age in Study II and under two years of age in Study I

causing different daytime sleep durations because of the decrease in the duration

of daytime sleep with increasing age (Iglowstein et al. 2003, Sadeh 2004).

In quantitative studies, an attempt is made by researchers to control

potentially confounding variables. Study participants’ characteristics could form

extraneous variables which are important to control. (Polit & Beck 2010.) The

crossover design used in Study II added validity when infants served as their own

controls and thereby controlled all confounding characteristics. It was not

possible to randomly assign infants to different order of treatments (outdoor and

indoor sleeping), which decreased the power of the crossover design. It is possible

that the ”first night effect” influences behavioral and physiological recordings

(Agnew et al. 1966), as the second condition is influenced by experiences in the

first (Polit & Beck 2010), but no carryover effect was found between outdoor

sleep duration and treatment order in the study, in line with other recent

publications (Kronholm et al. 1987, Katz et al. 2002).

Although the sample size was quite small in Studies I–III, it provided

significant correlational findings on some variables. Statistical conclusion validity

concerns the extent to which the conclusions about relationships and differences

drawn from statistical analyses reflect reality. There is a greater risk of a Type II

error with small samples, which can lead to the false conclusion that there are no

differences between the groups, even though the groups are different in reality.

(Burns et al. 2011.) It should be noticed that the correlations in Studies II and III

do not imply causality, even if relationships between variables were strong (Polit

& Beck 2010, Burns et al. 2011). The relationships in correlational research are

the means for generating hypotheses to guide experimental studies for examining

cause-and-effect relationships (Burns et al. 2011).

External validity concerns the degree of generalizability of the results (Polit

& Beck 2010). With caution, the findings of Study I are generalized to concern all

children under two years of age and the findings of Study II and III all children

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about three months of age who sleep outdoors in the winter. Because of the

possibility of selection bias, i.e. that only those families who had higher well-

being and who had children with no sleeping problems participated in Study II,

the results are generalized at least to such families. The results of the

questionnaire study showed that almost all parents (91%) thought that they were

happy to have their child sleep outdoors. The proportion of families with good

experiences about children sleeping outdoors in winter is thus high, increasing

external validity. Study II was performed in natural settings, which increases the

generalizability of the findings to everyday lives of the families. If tight control

aimed to maximize internal validity would have been exercised in the study, the

setting could have become too artificial to be generalized into a more naturalistic

environment (Polit & Beck 2010).

Reliability means the consistency of the measurement method (Burns et al.

2011). Internal consistency of the questionnaire (Study I) was evaluated by

calculating Cronbach’s alpha, the results of which ranged between 0.6 and 0.81.

As reliability of 0.80 is usually considered to show a strong coefficient for a scale

(Burns et al. 2011), some parts of the questionnaire are reliable, while some parts

still need restructuring. The degree of error and bias in temperature readings is

low. The tests can be repeated by other researchers and the results should be the

same. Therefore they are verifiable and replicable.

The reliability in structure observations refers to the consistency of how

strictly observations and records could be performed in the same way each time

they take place (Parahoo 2006). All observations were done by the same

researcher with several years of experience in pediatric nursing. Also infants’

mothers were present, observing and evaluating the falling asleep and awakenings

of their infants.

The use of a thermal manikin for measuring heat loss is relevant, reliable and

accurate, and the method is quick, easily standardized and repeatable. Thermal

manikins have been used for research purposes for more than 60 years. (Holmer

2004.) Manikin measurements have produced good reproducibility and agreement

with clothing trials (Anttonen et al. 2004, Meinander et al. 2004). However, the

manikin had a simple shape without toes, fingers, eyes, mouth, ears and nose, all

of which would increase the heat transfer. Only measurements on human subjects

in natural settings and actual conditions of movements and wind would directly

provide correct insulation results (Havenith 1999). Thermal insulation of specific

bedding will vary according to its arrangement over the baby; whether the covers

are loosely draped over the body or tucked in tightly (Kerslake 1991). To ensure

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the reliability of the clothing insulation study, three measurements were made for

each clothing ensemble, and the results given in this study are the arithmetic mean

of single test results. The coefficient of variation (CV) of clothing ensembles’

insulation (It) was less than 7%. Replications should be within 10% of the mean

value of the three measurements (ISO 9920 2007).

6.2 Trustworthiness of the qualitative study

Trustworthiness of Study IV was discussed through credibility, dependability,

confirmability and transferability, which are the criteria developed for the

evaluation of qualitative research (Lincoln & Guba 1985).

Credibility means confidence in the truth of the data and their interpretations

(Polit & Beck 2010). Finnish mothers who had varying amounts of experience

about children sleeping outdoors in winter were recruited from a large geographic

area. Sometimes it was hard for a researcher who is also a mother of children who

sleep outdoors to see something that was obvious because cultural thinking

shapes our interpretations (Connolly et al. 2006). On the other hand, having

similar experiences made it easier to understand the phenomenon more deeply.

The researcher familiarized herself more closely with the study phenomenon

during the observational study and skin temperature measurements, which helped

to formulating research questions and with analysis. The same researcher

conducted and analyzed all interviews. During the development of categories

looking forwards towards the overall results of the analysis as well as looking

backwards towards the data was needed. It was not possible to have a holistic

view just somehow simply emerge from an accumulation of detailed

categorization. (Dey 1993.) Two participants in the interviews performed

member-checking for increased credibility (Lincoln & Cuba 1985). The contents

of the generic and main categories were agreed by participants; only some sub-

categories were combined.

Dependability concerns the stability of data over time and over conditions

(Polit & Beck 2010). Three pilot interviews were conducted to test the research

questions. Similar question areas, but sometimes in different order, were used

with all the participants, and supportive questions were used to help the mothers

describe their perceptions. The analysis process was discussed and agreed with

the co-authors of Study IV.

Confirmability is concerned with the objectivity and neutrality of the data, so

that the findings reflect the participants’ voice and conditions of the inquiry (Polit

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& Beck 2010). Mothers’ original expressions were used in reporting. The

limitation in confirmability is that the mothers used local dialects, and the rich

nuances of the expressions they used were lost when they were translated into

English. Confirmability was also confirmed by two participants’ member

checking and agreement on the information provided by the participants.

Transferability deals with the extent to which the findings from the data can

be transferred to other settings or groups (Polit & Beck 2010). The context,

inclusion criteria and participants’ characteristics have been described as clearly

as possible (Polit & Beck 2010). The findings can be transferred to families with

outdoor sleeping children in a northern winter environment.

6.3 Discussion of the results

6.3.1 Winter environment in Northern Finland

The winter environment in Northern Finland was highly valued, and parents

wished that their children would also adopt a life-style that was close to nature. A

strong northern place-identity was formed, which emerged when mothers

described their dimensions of northern winter experiences. Mother’s

‘environmental past’ (Proshansky et al. 1983) had an effect on how they

experienced the cold environment, what their place-identity was like and how the

harsh environment also created psychological well-being and health (Korpela

2002). This respectful attitude towards nature partly affected the experiences of

some mothers in that winter environment was seen as a positive affordance, as

described by Gibson (1986), and as an ideal setting for children to sleep although

the weather was harsh and changeable and it was dark in the winter.

Fresh air was thought to be healthy for the child and one of the main reasons

for letting the child sleep outdoors in the winter. Already Florence Nightingale’s

first rule of nursing was: “to keep the air he breathes as pure as the external air,

without chilling him” (p. 34) and she emphasized that “the main want of baby is

always to have fresh air” (Nightingale & McDonald 2001: 148). However, during

the winter temperature inversions may play a major role in air quality when

pollutants are trapped near the ground, leading to poor air quality (National

weather service forecast office 2011). The air of northern city environment was

sometimes observed by mothers to be polluted, and this viewpoint highlights the

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question of the healthfulness of outdoor sleeping during frosty weather with calm

winds.

The temperature of infants’ outdoor and indoor daytime sleeping environment

and the weather outdoors varied markedly in Northern Finland during the winter.

Point of comparisons between other cultures with ambient air temperatures

outdoors during the infants sleep was not found. The measured room temperatures

in which study infants slept were higher during daytime sleep than those

measured in Britain in the winter (Wailoo et al. 1989b) and during the nights in

New Zealand (Baddock et al. 2004). The temperature difference between outdoor

and indoor ambient air can be 50°C in Finland posing challenges to the families

for offering appropriate sleeping arrangements to their child and require

knowledge and experiences to manage.

The interviewed mothers in this study described how greenhouse effects had

caused different shorter winters with warmer weather. This could cause

decreasing experiences of cold weather events and how to protect from cold.

Climate change affects all people (Guidotti & Gitterman 2007), but still there is a

lack of empiric data on the specific effects of climate change on children

(Bunyavanich et al. 2003). Weather conditions such as storms, heat waves and

cold snaps, create increasing challenges and responsibility for protecting children

(Guidotti & Gitterman 2007, Pronczuk & Surdu 2008). In the news, there was

reported for example that in Peru, at least 46 children died during one of the

coldest spells in 30 years in 2004 (BBC NEWS 2004) and in Chile, the coldest

July since 1908 was in 2010 (MercoPress 2010a) causing increase of respiratory

problems in children (MercoPress 2010b). Knowledge of cold protection of

children is a current topic despite global warming and even because of it

highlighting the importance of sharing “snow-how” globally.

6.3.2 Cultural knowledge-building

The premise of the childcare practice of children sleeping outdoors in winter is

nowadays generally in accordance with the earlier premise introduced by

pediatricians such as Arvo Ylppö since the 1920s. It has always been considered a

practice that promotes children’s well-being, although the aims have shifted from

the prevention of diseases, such as rickets, to the promotion of health and

comprehensive well-being of children and families. The reasons behind and

meanings assigned to particular practices can change over time as culture is

historically produced through interaction with changing economic, social, and

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political factors. Infant care practices can differ between cultures and yet be

justified in similar ways or practices may be similar but the meanings of those

practices may vary. (Abel et al. 2001.)

This culturally bound childcare practice has its historical backgrounds (Ylppö

1921, Ylppö 1939, Ylppö 1947), the know-how on which has traditionally been

passed on from one generation to another. The guidelines have been based on this

historical background and have been distributed to the parents by the public

health services. Female family members and friends have had an important role

and influence on infant care practices in New Zealand (Abel et al. 2001) just like

in this study in Northern Finland. Parents’ own positive experiences have

strengthened continuity and their desire to recommend practices to their own

children as well.

Cultural knowledge-building related to children sleeping outdoors in the

winter has been a prerequisite for the practice, as knowledge grew little by little

with increased experience in a changing society. When lack of clothes could

earlier prevent mothers from letting their children sleep outdoors (Punto 1991),

there are now many kinds of prams available and the maternity package is

distributed to parents (Kela 2009). Without this growing knowledge, more

adverse effects could exist among infants. Stahl (2000) described the knowledge-

building process as consisting of cycles of personal and social knowledge-

building. Personal beliefs are entered into a social process of interaction with

other people and shared culture. Alternatives expressed in public statements and

other people’s statements are discussed, providing a rationale for different points

of view and converging to a shared understanding. Collaborative knowledge is

formed, formalized and objectified into cultural artifacts, which are used in

activity (Stahl 2000). Shared knowledge is the understanding of the same

historically accumulated knowledge, values, perspectives artifacts and ways of

life (Stahl & Hesse 2009).

In the city of Oulu, almost all parents let their children to sleep outdoors

showing the practice to be common. This was consistent with a study by the

Reima group (2009), which showed it to be more common in Denmark and a

popular practice in Norway and Sweden as well. No other international studies of

the prevalence of the outdoor sleeping practice were found. Instead, cultural

comparisons have been made between bedsharing, cosleeping and sleeping in

separate rooms, and different kinds of arguments for and against can be found. In

cold environments such as in Mongolia (Tsogt et al. 2006), Peru (Tronick et al.

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1994) and Finland, different childcare practices can be found, all of which have

the same aim, i.e. to protect the child.

In this study, mothers who were interviewed were stimulated to discussion

when they had been in contact with different cultures where the outdoor sleeping

practice was not common; it was not understood by persons outside the culture

although it was taken for granted in the Nordic cultures. This was consistent with

the thought of Connolly (2006), who discussed cultural practices. Cultural

similarities and differences can be found in infant care practices and beliefs (Abel

et al. 2001), which goes to the core of cultural understanding of children’s health

and well-being (Morelli et al. 1992).

Adverse and beneficial health effects should be weighed and evidence-based

information provided to fit the individual needs as well as complex cultural

contexts of families (Morgan et al. 2006). Nelson et al. (2000) highlight the

significance of understanding child care from a cross-cultural perspective in SIDS

research pointing out the need to modify health educational messages for certain

cultural groups. Weaving the safety needs of the infant into family dynamics and

culture is a challenging task (Casey 2007), and more important than ever during

this time of international migration. As Melendez (2005) has discussed in her

review, immigrant families in the United States have to make choices concerning

childcare practices between their own values and the practices of their host

society and surrounding culture. Cultural sensitivity is needed by those who work

with families. (Melendez 2005.) It is important to be aware of the background and

meanings of childcare routines, not only take them as a self-evident practice. This

makes it possible to see even possible adverse effects more exactly and protect

the child effectively. Understanding is needed on how parents structure infants’

sleep, and what their goals and expectations are, and through awareness of these

factors parents may choose certain sleeping arrangements over others. (McKenna

& Volpe 2007.) It is important to understand cultural differences in beliefs and

practices for successful delivery of health recommendations (Abel et al. 2001).

6.3.3 Family well-being

A prerequisite for family well-being was safety perspectives, which had to be

taken into account accurately. Many risk factors related to the child, physical and

social environment were mentioned. Mothers had to observe their outdoor

sleeping babies frequently and protect them against risk factors. However, many

parents had not encountered dangerous situations and when comparing different

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cultures, they felt the Finnish northern environment to be safe, which is one of the

factors of a healthy environment (Taylor & Repetti 1997) that impact beneficially

on the family’s sense of well-being (Åstedt-Kurki et al. 1999).

Shared cultural knowledge is seen in everyday routines (Weisner 2002).

Mothers act according to the cues from Finnish culture letting their child sleep

outdoors in the winter, which is seen as appropriate place-related behavior (Miller

et al. 1998). “Goodness of fit” between mother’s goals, activities, and

surroundings (Wicker 1972) can be reached enhancing family well-being.

Sometimes negative effects were also experienced.

In addition to satisfying the child’s sleep needs, mothers had wider goals of

providing healthy childcare and wanting their children to adopt a lifestyle that

would be in tune with the natural environment. As Like Wells & Lekies (2006: 13)

have described: “When children become truly engaged with the natural world at a

young age, the experience is likely to stay with them in a powerful way – shaping

their subsequent environmental path” (Wells & Lekies 2006). When concrete

goals are being attained it also promotes reaching larger, more abstract goals, thus

increasing the importance of concrete goals (Carver & Scheier 1998) such as

mothers’ everyday goal of putting their children outdoors to sleep.

According to McKenna et al. (2007) the majority of parents feel that it is an

alien idea to have the infant sleep alone. Yet, in the postindustrial west, solitary

sleep is thought to be modern, healthy, and normal way (McKenna et al. 2007).

Cosleeping promotes closeness in cultures where interdependence is the goal of

the childcare practice, whereas solitary sleeping promotes individualism in other

cultures (Morelli et al. 1992). The connection between the outdoor sleeping

practice and promotion of desirable socialization goals such as independence in

American families (Jenni & O'Connor 2005) did not exist in the data of this study,

despite the great distance when the child is sleeping outdoors in the garden and

the parents are indoors. Families with outdoor sleeping practice may also have

habit of bedsharing during other sleep episodes.

Positive attitude on the part of the community towards outdoor sleeping have

confirmed that the practice is now firmly rooted in our culture and is popular.

This strong attitude may have caused that sometimes the outdoor sleeping

practice has been felt as an activity of “good mothers”, leading to feelings of

failure and guilt if it is not successful. In the study of Morelli et al. (1992),

mothers justified their infant sleeping arrangements with reference to norms of

good parenting and the infant’s needs and development. The mothers they

interviewed who were not able to achieve the goal of traditional sleeping

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arrangements of infants were unhappy because they were aware that they did not

comply with conventional practices. Salonen et al. (2008) found that parents in

Finland experienced low self-efficacy related to infants’ daily rhythm and sleep.

The outdoor sleeping episode has become a building block of everyday life

creating fluency by its rhythm and regularity, which children were found to need

as early as the late 19th century (Stearns et al. 1996) and which is seen as one of

the characteristics of good childcare in Dutch parenting (Super et al. 1996). Daily

routines are an important aspect of family health (Denham 1999, Denham 2002,

Fiese et al. 2006) and well-being (Vuori & Åstedt-Kurki 2009).

Furthermore, when the child takes longer daytime naps outdoors and his/her

sleep need satisfied, it has broader effects on family well-being. Mothers have a

moment of their own and get a chance to have a break that could promote

parenting, according to Schwichtenberg et al. (2011). Children who take more

naps may experience more positive maternal attention (Schwichtenberg et al.

2011), showing that infant sleep and parenting competence and well-being are

influenced by complex relationship systems, as shown by the transactional model

(Sadeh et al. 2010). At its best, the outdoor sleeping episode is a shared good

experience that evokes larger positive effects to family well-being. Mothers tried

to find a balance between the child’s and parents’ needs in the northern winter

environment and it was possible to reach the situation of goodness of fit. The

outdoor sleeping childcare practice is a desirable custom when it promotes family

well-being, but the child’s needs and safety come first.

6.3.4 Winter clothing of outdoor sleeping children

The selection of thermal insulation of clothing was not always sufficiently based

on outdoor air temperature, and traditional infant care practice was not always

precise enough to maintain infants’ thermal comfort in a cold outdoor

environment. In the study of Wailoo et al. (1989a) and Wigfield et al. (1993)

mothers applied more insulation when it was colder, instinctively providing

appropriate thermal conditions, whereas studies were also found where infants

were dressed inappropriately (Nicoll & Davies 1986, Tuohy & Tuohy 1990,

Bacon et al. 1991). All these studies were implemented indoors in quite stabile

thermal condition while mothers in northern winter encountered more challenges

in varying weather conditions.

The infants were like swaddled during outdoor sleeping when mothers

bundled them up in layered clothing and sleeping bags, restraining their

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movements when they slept in the pram. Cold environment makes it possible to

use this kind of swaddling without overheating of the infants.

Mothers found the most appropriate thermal insulation of clothing at around

−5°C when the observed and required insulation values were equal. The Finnish

maternity package and pram gives appropriate insulation at −5°C, providing

explanation for this. Our findings in the questionnaire study (Study I) also support

the notion that the best temperature for letting the child sleep outdoors is about

−5°C. There is a bigger risk that infants do not reach thermal balance when it is

colder or warmer than −5°C. Fine adjustment is needed in the selection of thermal

insulation of clothing in other outdoor temperatures than −5°C.

The maximum amount of clothes gave appropriate insulation in ambient

temperature of about −17°C, but it should be noticed that by limiting the duration

of cold exposure, letting the child be outdoors is possible, but not desirable, in

colder weather. When the insulation of infant’s clothing is less than the required

insulation, the body cannot maintain thermal balance during a long nap outdoors,

which is why sleeping time has to be limited to prevent progressive cooling (ISO

11079 2007).

Our study shows that the thermal insulation of the clothing of infants sleeping

outdoors has important significance in terms of reaching goodness of fit between

the child, family and northern winter environment. The cooling rate of Tsk.

increased when the deficiency in thermal insulation increased, and in this kind of

situation, infants slept for a shorter time. This is in line with the study of Eiser et

al. (1985), in which mothers reported that the infants became irritable when too

cold.

A slow cooling of Tsk was observed even when the difference between

observed and required thermal insulation was ≥ 0 clo caused by either diurnal

variation, a sleep-induced decrease in body temperature or return to normal

temperature after initial overheating due to dressing procedures indoors. Before

going outdoors, infants were dressed in layered winter clothes and put in prams

indoors, causing heat accumulation and higher skin temperature at sleep onset

when compared to indoor sleeping.

Vasoconstriction showed that infants were not always sleeping at

thermoneutral temperature and their thermoregulation processes were activated.

Sometimes infants were also too heavily clothed, which was seen as higher level

of Tsk and relative humidity inside the clothing. This is consistent with the

findings of Grover et al. (1994), where bundling a healthy infant in a temperate

environment caused an increase in skin temperature. Of the different skin sites,

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cheek temperature showed the biggest positive correlation with microclimate

humidity measured on the chest. This suggests that the head plays an important

role in heat loss, as also shown by previous studies where most of the heat loss in

dressed infants has occurred via the head (Stothers 1981, Elabbassi et al. 2002),

especially via the face (Nelson et al. 1989). Elabbassi et al. (2002) have cautioned

against reducing heat loss from the head of heavily dressed newborns, which was

suggested to contribute to overheating of the brain, and Mitchell et al. (2008)

have recommended avoiding head covering as part of SIDS prevention strategies.

Special attention should therefore be given therefore to cold protection of the

head of outdoor sleeping infants to avoid overheating and cooling alike.

Excessive bedding and clothing causes overheating, and its relevance to SIDS

has been widely studied (Nelson et al. 1989, Fleming et al. 1990, Ponsonby et al.

1992, Wigfield et al. 1993, Wilson et al. 1994, Watson et al. 1998, Baddock et al.

2004, Wilson & Chu 2005), but hardly any studies were found related to the

association between SIDS and too little thermal insulation (Williams et al. 1996).

It should be taken into account in interpretations that children are individuals,

as pointed out by one of the interviewed mothers who had noticed that her child

who had Down’s syndrome reacted differently to cold. The type and intensity of

cold exposure and many individual factors interact with cold-related symptoms

(Stocks et al. 2004). Special attention should be paid to thermal insulation of

clothing in the case of children with neurological disorders with cold extremities

(Svedberg et al. 2005) and Raynaud’s phenomenon (Nigrovic et al. 2003) because

of their increased risk of frostbite and higher level of stress reaction if they are

allowed to sleep outdoors. Moreover, facial cooling alone with inhalation of warm

air can increase bronchoconstriction in children with mild asthma (Zeitoun et al.

2004).

Scientifically based guidelines of children’s cold protection and sleeping in

varying weather conditions should still be considered. Hull et al. (1996a,b) have

suggested to giving general advice and reinforcing parents’ awareness of infants’

sweatiness and coldness and adjusting the amount of clothing insulation in

accordance with ambient air temperature, rather than giving more specific advice,

due to the individuality of infants and wide variation in their sleeping metabolic

rates.

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6.3.5 Well-being of the children

Sleep. The findings of both the questionnaire and the observational study show

that among well-clothed children, the duration of outdoor sleep is longer

compared to indoor sleep. The average duration of outdoor sleep episode was

longer and that of indoor sleep shorter when compared to other studies of children

at the age of about three months sleeping indoors (Iglowstein et al. 2003, Sadeh

2004, Sadeh et al. 2009). Morgan (2006) has brought out the thought that long

sleep duration would not be the best practice nutritionally. It would also be a new

viewpoint in terms of SIDS research in Scandinavia that if long outdoor sleep

duration were taken into account the SIDS risk per slept hour might in many cases

be greater outdoors than indoors.

One suggestion for the long duration of outdoor sleeping could be restriction

of movements by winter clothing and sleeping bag, as swaddling has been shown

to increase duration of sleep (Gerard et al. 2002, Franco et al. 2005) and may help

infants return to sleep spontaneously, limiting parental intervention (Gerard et al.

2002). During outdoor sleeping auditory stimuli are reduced by hats, sleeping

bags and prams, preventing the effect of less intense auditory stimuli needed to

incur arousal when swaddled (Franco et al. 2005).

Soothing techniques and the location of sleep have been shown to affect

infant sleep (Sadeh 2004). Sleeping in a pram outdoors could be the same kind of

situation as falling asleep and sleeping alone in a crib in a separate room, which

has been shown to improve the possibilities of infants to sleep through the night,

with fewer night awakenings. It has been suggested that parents of such infants

are less likely to notice when their infant wakes up because of the distance and

visual separation (Sadeh 2004). Outdoor sleeping could promote infants’ own

self-regulation and self-soothing skills, the lack of which could cause shorter

sleep (Sadeh et al. 2010).

Parents familiarized their children with outdoor sleeping by starting with a

short duration. Children may learn to sleep outdoors so well that it is difficult to

try to have them sleep indoors. An antecedent stimulus may encourage the

behavior that has been linked with the stimulus. The stimulus serves as a trigger

for the desired behavior. Over time, bedtime routines in a familiar environment

become associated with the onset of sleep. (Wiggs 2009.) In the same way,

dressing the child in winter clothing and putting the child out serve as an

antecedent stimulus and help the child fall asleep.

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Interaction between sleep and thermoregulation. Cold exposure was not the

factor that made children sleep longer. This study showed infants’ high sensitivity

to cold, when a slight cooling rate caused awakening and decreased the total sleep

time in a cool environment. Previous studies confirm this, as findings show a

decrease in total sleep time in unclothed neonates due to cold exposure (Bach et

al. 1994, Telliez et al. 1997). However, Hey and O’Connell (1970) have presented

a contrasting finding: well-clothed infants who were exposed to a cold

environment slept quietly even when heat production was increased, suggesting

that swaddled infants may not cry or call for attention even if they are under

severe cold stress. It could be hypothesized that a slow enough cooling rate due to

good clothing is under the infants’ threshold and during long duration of sleep

skin temperature can decrease without awakening the child. The skin is quite

insensitive to slow rates of temperature changes that cause adaptation (Parsons

2003). The thresholds for warm and cold stimuli increase when the rate of

temperature change becomes small (Kenshalo 1990). In previous studies on

infants’ sleep in cool exposure (Azaz et al. 1992, Telliez et al. 1997, Bach et al.

2000a, Bach et al. 2001, Telliez et al. 2004), the correlation between cooling rate

of Tsk and sleep duration has been ignored, although it is essential in relation to

sensations in a cold environment.

A correlation was not found between the rate of rise of Tsk and sleep duration

indoors. This is in line with the findings of Bach et al. (1994), where neonates’

sleep was not disturbed by exposure to warm temperatures. The threshold is

higher for the rate of rise than the rate of fall in skin temperature (Libert et al.

1979), and there is stronger sensitiveness to cold than to warm in all body sites

(Stevens & Choo 1998). During outdoor sleeping sweating of infants was

observed, and humidity increased quite evenly when Tsk increased. In the study of

Werner and Reents (1980), evaporation started to increase rapidly when the

ambient air temperature rose above 30°C.

Central-peripheral temperature difference has been shown to be a better

indicator of the thermal state of the child than a single skin temperature

measurement alone (Lyon et al. 1997). Those infants who had a slow cooling rate

and were outdoors for about 200 min or more (n = 10) had an increase of more

than 2°C in central-peripheral temperature difference. A difference of more than

2°C may have an effect on heart rate and blood pressure of very low birth weight

infants (Lyon et al. 1997). For this reason it would be better to limit the duration

of outdoor sleep to less than 200 min, especially if it is colder than −5°C. The

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cooling-induced awakening of infants may interrupt the cold exposure before

cooling appears if the cooling rate crosses the threshold.

The findings indicate that the infants had in some cases cold stress; peripheral

vasoconstriction was found as there was a significant increase in the central-

peripheral skin temperature difference during outdoor sleeping and significantly

lower temperatures of the extremities at the end of outdoor sleeping compared to

indoor sleeping. Coldness of hands and feet was also observed by palpation.

Thermoneutrality was not maintained in 85% of the infants sleeping outdoors, as

Tsk fell more than 0.3°C/hour, if the definition of thermoneutrality is viewed

according to Sauer et al. (1984). However, the proportion of infants who reached

thermoneutrality could be higher because study infants were older and body

weight greater than in the study of Sauer et al. (1984). Skin temperature of the

chest at the end of outdoor and indoor sleep did not differ significantly, which

shows that cooling-induced vasoconstriction had first taken place in peripheral

vessels, but cooling had not proceeded to hyporthermia. The interviewed mothers

described how they checked their outdoor sleeping infants’ temperature by

palpating the cheeks and nape. It is possible to feel sweatiness by palpating the

nape, but it is not the right place to feel coldness, because nape temperature

remains warm during cold exposure due to the action of brown adipose tissue

(Silverman et al. 1964, Rylander et al. 1972).

It was interesting to find that mothers tried to protect their children from

cooling as they had noticed a correlation between cooling and the common cold.

An association was found between cold outdoor temperature and humidity and

respiratory tract infections among adults in the study of Mäkinen et al. (2009). On

the other hand, some mothers saw sleeping in a cold environment as toughening

the child, which is line with findings among Swedish mothers (Welles-Nyström et

al. 1994).

A white and bluish area on the child’s cheek was reported by some parents. A

white area seems to be frostnip, which is superficial cooling of tissues without

cellular destruction (Marx et al. 2010), whereas a bluish area might be a chilblain,

a form of cold injury representing the next stage of severity (Giusti & Tunnessen

1997). The low amount of frostbite injuries reported in previous studies in

Finland (Juopperi et al. 2002, Koljonen et al. 2004) was confirmed in this study,

as no other frostbite injuries came up.

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6.4 Summary of the findings and conclusions

1. The winter environment in Northern Finland with pure air and peaceful, fresh

and clean nature can be seen as an affordance for the child sleeping outdoors.

2. During daytime, infants usually sleep outdoors once a day in different kinds

of conditions, from sunshine to heavy snowfall, with ambient air temperature

decreasing almost to −30°C.

3. The best temperature for outdoor sleeping was shown to be −5°C.

4. Outdoor sleeping is a self-evident and common culturally bound custom in

Northern Finland.

5. Guidelines, advice and encouragement about having children sleep outdoors

were given to mothers from different sources. Mothers built their own

personal knowledge through their experiences and shared it with others, at the

same time participating in the cultural knowledge-building processes. The

outdoor sleeping childcare practice is a commonly accepted collective, a type

of behavior that is sometimes felt to be compulsory.

6. There are many risk factors involved with the outdoor sleeping practice, but

when all security perspectives are taken into account it can promote family

well-being by creating a rhythm and strengthening the fluency of everyday

life.

7. It was difficult to adjust systematically the optimal thermal insulation for

outdoor sleeping infants during northern winter. When ambient temperature

decreased, the cooling rate of Tsk increased, suggesting that the cold

protection of the clothing compensated only partly for the increased heat loss.

Both cooling and sweating existed.

8. Specific guidelines on clothing are needed for parents.

9. Maximum amount of clothes combined with a pram can provide appropriate

insulation in ambient temperature of about −17°C.

10. Children sleep longest sleep outdoors when the cooling rate of Tsk is minimal.

11. Outdoor sleeping promotes satisfying children’s daytime sleep needs as it

increased the duration of sleep.

12. Infants should not sleep outdoors for more than three hours because a slow

cooling rate that remains under threshold could increase cold stress.

13. Outdoor sleeping was thought to promote children’s health.

14. A comprehensive view of the phenomenon was gathered in the evaluation

model of outdoor sleeping episode (Figure 5). It provides a tool for

systematic evaluation on each different level and between levels, shifting the

98

pointer of goodness of fit either to the direction of beneficial or adverse

effects.

6.5 Implementation and suggestions for future research

This study gives information about outdoor sleeping that can be applied to

practical problems encountered by parents. Families who move to Finland can

familiarize themselves with a childcare practice that they may even never have

heard of by reading this study. It also provides support to families who move

abroad, helping them describe a practice that is self-evident to them, but which

may seem peculiar to others.

The evaluation model of outdoor sleeping episode can be utilized in nursing

practice when public health nurses give counseling to families. It helps to identify

relationships between different levels and broader aspects that should be noticed

in guidelines. The model (Figure 5) can be used as a tool when giving counseling.

More specific guidelines are needed in Finland, and the study findings also

provide detailed information, for example about required clothing insulation in

different outdoor temperatures.

In nursing science, when mixed methods are used to study different kind of

phenomenon, findings can be compiled and utilized with the mixed methods

evaluation model (Figure 5), developed in this study. The questionnaire used in

Study I still needs improvements, and the evaluation model of outdoor sleeping

episode need testing.

This study prepares the ground for international comparative studies. Cultural

comparisons allow us to understand better children’s sleep in different contexts

and to evaluate the benefits and consequences of different cultural sleeping

practices (Giannotti & Cortesi 2009). Hardly any other studies addressing the

outdoor sleeping childcare practice can be found, and for that reason it would be

of great significance to add questions about outdoor sleeping into international

questionnaires, such as the Brief Infant Sleep Questionnaire (BISQ), used to study

bed sharing and room sharing (Sadeh 2004, Mindell et al. 2010a). Internationally

collaborative and broadly interdisciplinary studies are needed (Jenni & O’Connor

2005) using both qualitative and quantitative approaches in the field of SIDS

research, where there is still a lack of knowledge dealing with correlations

between outdoor sleeping, cooling and SIDS.

This study concentrated on the thermal environment, but not on the quality of

indoor and outdoor air, which are also important factors when evaluate the

99

healthfulness of the outdoor sleeping practice. Information about connections

between morbidity, such as falling ill due to infections, and cooling caused by

outdoor sleeping is still needed. In the next phase, more extensive

epidemiological studies and experimental research is needed to attain inferences

from causal relationships.

Future research is needed to find out the effects of extreme weather events on

children and to gain more knowledge about children’s environmental health.

100

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121

Appendix Clothing insulation tests and information about clothing

CL

OT

HIN

GIN

SU

LA

TIO

NT

ES

TS

:

B1.

AB

BR

EV

IAT

ION

S:

Type

ofcl

othe

s:L

isto

fcl

othe

s:U

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derc

loth

es1,

2,3

U1 UU1

2.

U2

unde

rclo

thes

1,2,

3,6

Bbl

anke

t5

M1

mid

-lay

er7,

8,12

,13,

M2

mid

-lay

er7,

8,9,

10,1

1,12

,13

U1

3.M

1

U1

M1

O1

4.

M3

mid

-lay

er7,

10,1

1,13

O1

oute

rwea

r14

a,15

b,17

O2

oute

rwea

r7,

14a,

15b

O3

oute

rwea

r14

b,15

a,16

,17

C18

U1

M1

O1

C1

5.

OC

C1

cove

rs18

C2

cove

rs19

Ssh

eeps

kin

20P

pram

21

U1

M1

O1

C1

6.P

U2

O2

C1

P7.

gabgnipeels.81

tiusydob.1ffu

mtoofretni

wdeddap.91

yppanelbasopsid.2

nikspeehs.02sgniggel

detoof.3marp.12

tiusrep

mor.4

U2

M2

O3

C2

S8.

UM

P

OC

P

5.bl

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tand

duve

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er6.

sock

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mit

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cks

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9.w

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nm

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hirt

and

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s)11

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hw

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ng12

.woo

len

card

igan

and

pant

s13

bala

clav

aha

t13

.bal

acla

vaha

t14

a.sn

owsu

it14

b.w

arm

ersn

owsu

it15

a.in

sula

ted

hat

15b

woo

len

hat

15b.

woo

len

hat

16.i

nsul

ated

mit

tens

17.i

nsul

ated

boot

ies

122

Un

der

clot

hes

:

LIS

TO

FC

LO

TH

ES

4ro

mpe

rsu

it

1.bo

dysu

it•

wei

ght:

61.1

g•

60cm

•10

0%

cott

on

4.ro

mpe

rsu

it•

wei

ght:

78.4

g•

60cm

•10

0%

cott

on

•10

0%

cott

on

2.di

spos

able

napp

y

3.fo

oted

legg

ings

•w

eigh

t:44

.3g

•60

cm

5.bl

anke

tand

duve

tcov

er•

wei

ght:

671.

3g

•bl

anke

tfi

llin

g:10

0%

•10

0%

cott

onbl

anke

tfi

llin

g:10

0%

poly

este

r,•

cove

r:52

%po

lyes

ter,

48%

cott

on•

blan

ketc

over

:100

%co

tton

123

Mid

-lay

er:

6.so

cks

•w

eigh

t:19

.7g

•si

ze:1

9-21

•78

%co

tton

,20

%po

lyam

ide,

lycr

a

7.gl

oves

•w

eigh

t:18

.7g

78%

20%

lid

l

9.w

oole

nm

itte

n•

wei

ght:

40.7

g

•78

%co

tton

,20

%po

lyam

ide,

lycr

a

8.w

oole

nso

cks

•w

eigh

t:38

.0g

124

12.w

oole

nca

rdig

anan

dg

pant

s•

wei

ght:

258.

2g

10.p

lays

uit

(shi

rtan

dpa

nts)

•w

eigh

t:14

5.9

g•

size

:70

cm•

100%

cott

on

11.o

vera

llw

ith

wad

ding

•w

eigh

t:28

6.6

g•

size

:70

cm

13.b

alac

lava

hat

•w

eigh

t:26

.1g

•si

ze:7

0cm

•10

0%

cott

on•

100

%co

tton

,w

addi

ng:1

00%

poly

este

r

125

Ou

terw

ear:

14a

snow

suit

15a.

insu

late

dha

t14

a.sn

owsu

it•

wei

ght:

470.

5g

•si

ze:6

8cm

•co

ver:

100

%po

lyes

ter,

fill

ing:

100

%po

lyes

ter

•w

eigh

t:62

.6g

•si

ze:5

0•

cove

r:10

0%

poly

este

r,fi

llin

g:10

0%

poly

este

r,fi

llin

g:10

0%

poly

este

r,li

ning

:50

%po

lyes

ter,

50%

cott

on

lini

ng:

50%

poly

este

r,50

%co

tton

bi

14b.

war

mer

snow

suit

•w

eigh

t:66

7.0

g•

size

:68

cm

15b.

woo

len

hat

•w

eigh

t:36

.1g

126

16.i

nsul

ated

mit

tens

•w

eigh

t:46

.9g

•si

ze:1

•co

ver:

100

%po

lyes

ter,

fill

ing:

100

%po

lyes

ter,

lini

ng:5

0%

poly

este

r,50

%co

tton

17in

sula

ted

boot

ies

17.i

nsul

ated

boot

ies

•w

eigh

t:58

.5g

•si

ze:1

•co

ver:

100

%po

lyes

ter,

fill

ing:

100

%po

lyes

ter,

fill

ing:

100

%po

lyes

ter,

lini

ng:5

0%

poly

este

r,50

%co

tton

127

Cov

ers:

20.s

heep

skin

ih

1152

7

18.s

leep

ing

bag

•w

eigh

t:43

8.0

g•

fabr

ic:1

00%

cott

on,

•w

eigh

t:11

52.7

g

fill

ing:

100

%po

lyes

ter

21.p

ram

19.p

adde

dw

inte

rfo

otm

uff

•w

eigh

t:90

0.3

g

128

129

Original publications

I Tourula M, Isola A & Hassi J (2008) Children sleeping outdoors in winter: Parents’ experiences of a culturally bound childcare practice. International Journal of Circumpolar Health 67(2–3): 269–278.

II Tourula M, Isola A, Hassi J, Bloigu R & Rintamäki H (2010) Infants sleeping outdoors in a northern winter climate: skin temperature and duration of sleep. Acta Paediatrica 99(9): 1411–1417.

III Tourula M, Fukazawa T, Isola A, Hassi J, Tochihara Y & Rintamäki H (2011) Evaluation of the thermal insulation of clothing of infants sleeping outdoors in Northern winter. European Journal of Applied Physiology 111(4): 633–640.

IV Tourula M, Pölkki T & Isola A (2011) The cultural meaning of children sleeping outdoors in Finnish winter: A qualitative study from the viewpoint of mothers. Manuscript.

Reprinted with permission from International Association of Circumpolar Health

Publishers (I), John Wiley and Sons (II), Springer (III).

Original publications are not included in the electronic version of the dissertation.

130

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THE CHILDCARE PRACTICE OF CHILDREN’S DAYTIME SLEEPING OUTDOORSIN THE CONTEXT OF NORTHERN FINNISH WINTER

UNIVERSITY OF OULU,FACULTY OF MEDICINE,INSTITUTE OF HEALTH SCIENCES, NURSING SCIENCE,INSTITUTE OF BIOMEDICINE, DEPARTMENT OF PHYSIOLOGY;FINNISH INSTITUTE OF OCCUPATIONAL HEALTH, OULU;NORTHERN OSTROBOTHNIA HOSPITAL DISTRICT;KYUSHU UNIVERSITY, FACULTY OF DESIGN, DEPARTMENT OF HUMAN SCIENCE