Remember the monk "finger trick" we had before on Neatorama? Well, that ain't nothin' compared to this: Tibetan monks that can control their body temperature using a yoga technique called g Tum-mo. This time, there's even a Harvard professor testing them to make sure there's no hanky panky:

In a monastery in northern India, thinly clad Tibetan monks sat quietly in a room where the temperature was a chilly 40 degrees Fahrenheit. Using a yoga technique known as g Tum-mo, they entered a state of deep meditation. Other monks soaked 3-by-6-foot sheets in cold water (49 degrees) and placed them over the meditators' shoulders. For untrained people, such frigid wrappings would produce uncontrolled shivering. If body temperatures continue to drop under these conditions, death can result. But it was not long before steam began rising from the sheets. As a result of body heat produced by the monks during meditation, the sheets dried in about an hour. ...

Snow and extreme cold outdoors did not even faze these guys:

In 1985, the meditation team made a video of monks drying cold, wet sheets with body heat. They also documented monks spending a winter night on a rocky ledge 15,000 feet high in the Himalayas. The sleep-out took place in February on the night of the winter full moon when temperatures reached zero degrees F. Wearing only woolen or cotton shawls, the monks promptly fell asleep on the rocky ledge, They did not huddle together and the video shows no evidence of shivering. They slept until dawn then walked back to their monastery.

http://www.hno.harvard.edu/gazette/2002/04.18/09-tummo.html