The thing that prompted me to post this question is an episode of "I Shouldn't Be Alive" I saw recently, in which a solo peakbagger gets badly injured in an avalanche and spends about 3 days crawling/limping his way out. After at least 2 days of no sleep, exhaustion and blood loss, he struggles to stay awake thinking he will die if he succumbs to sleep. He falls asleep anyway and wakes up the next morning under a pile of fresh snow, feeling surprisingly refreshed.

The guy was super fit, which is always a great asset, but still he was wearing minimal clothing in subfreezing weather while tired & injured.