I don't know if any of you have read this, but I enjoyed the hell out of it, and it helps me "meditate upon [my] frailty as a creature of temperature, and upon man's frailty in general, able only to live within certain narrow limits of heat and cold." It's apparently well known and oft cited in the temperate zones about which it was written.
So, anyway, if you have not read it, here it is: http://www.jacklondons.net/buildafire.html and if you have, isn't it cool (so to speak.)
Colin.