When I worked in Japan, I once saw pearl divers working in the frigid winter ocean. Pearl divers are traditionally women and have been doing it the same way for centuries (though not many left). As far as I could tell, they only wore these cotton (definitely NOT waterproof) suits (they look sort of like those hooded, white, Tyvek hazmat coveralls) and a face mask. I was freezing my behind off watching from shore on a blustery, grey day as these women would work in the cold water for quite a long time. Amazing. They would climb out of the water and warm themselves up periodically in the boat, but I know that if I fell in that water, the shock of that cold water would probably make my whole body spasm into one big, painful knot in about 2 milliseconds.

And don't ice climbers acclimate their hands by submerging them repeatedly in ice water? I think I read that it trains the blood vessels to not constrict when exposed to cold. Last thing you need when hanging 200 feet up a frozen waterfall are useless hands. <img src="/images/graemlins/smile.gif" alt="" />