Have you heard of the "Iceman", Wim Hof?
Wim Hof (born 20 April 1959) is a Dutch daredevil[1], commonly nicknamed "The Iceman" for his ability to withstand extreme cold,[2] which he attributes to exposure to cold, meditation and breathing techniques (similar to the Tibetan technique Tummo).[3]
http://www.icemanwimhof.com/
https://en.wikipedia.org/wiki/Wim_Hof