Ryan F. wrote, "I am glad there was this thread, it helped me with the whole winter thing. It is my favorite time to go out, but there is less on going light in the winter than the rest of the year. I learned alot. I just cant wait for RJ to go so we can see if a sane person can really survive with this little gear. ( I am not one to talk, I tried a 50 degree bag at 15)"
I suppose some might debate if he is sane or not, but check out the "Iceman"--real name Wim Hoff.
He apparently has started to train people to do similar things as he does. Seems to be based around a combination of practicing Tumo meditation (Tibetan Buddhism roots), strong belief and will, and a lot of practice and acclimating oneself. He's not the only one who can do this, but probably one of the most recognized. Tibetan Monks have been doing similar for centuries.
I'm debating whether or not i want to try this route myself. I have had spontaneous meditation experiences wherein my body temperature raised quite a bit despite that my core temp had earlier gone down from relaxing/laying down and doing nothing physical for over 20 mins.