http://www.perfectbreathing.com/stay-warm-winter-qi-gongs-tumoFirsthand account

http://voices.yahoo.com/tumo-breathing-technique-warms-body-cleanses-8530461.htmlSummary

http://www.lifepositive.com/Spirit/world-religions/buddhism/tumo.aspTibetan Buddhist Dynamic Visualizations (theologically-charged) / remember that Buddhism closer to India/Tibet will have a Hindu overtone, as Siddhartha (i.e. Buddha) was a Hindu. The religion itself, in its more original forms, found in India/Tibet/Nepal actually make sense with the narrative stories of Siddhartha. When it goes into China, Vietnam, Japan, etc. the buddhisms plural there have synchronized to their regions and worldviews. Even the Zen practice of the Shaolin monks does not reflect the Zen of Japan's monks and the samurai. However, there is evidence that this style of breathing practice spanded more that just Tibet/India (probably came over from India), but died out other places. I'll put examples below from Japan in the 1500-1600's.

http://en.wikipedia.org/wiki/TumoGood wikipedia article

http://books.google.com/books?id=q4UbYjoz0-EC&pg=PT79&lpg=PT79&dq=tumo+breathing&source=bl&ots=pm79e2aY7O&sig=_KfvweIwfFnI7BxtDZNWo3bUv_k&hl=en&sa=X&ei=waT6UbToBpPG9gSk7YC4Ag&ved=0CEwQ6AEwBzgU#v=onepage&q=tumo%20breathing&f=falseVery good concise book exerpt

http://en.wikipedia.org/wiki/Wim_HofWim Hoff

http://www.youtube.com/watch?v=nRsNh0eB-IoWim Hoff

http://www.youtube.com/watch?v=Y1ial3Rc7XgWim Hoff method explained by himself

http://www.youtube.com/watch?v=5Arr4C52grQDiscovery Channel clips of Wim Hof