[scott_karana]

"Uncomfortably cold" is quite an understatement, when talking about allegedly "human" temperatures.

Sure, at 100, healthy humans can survive as long as their increased water needs are met. (Sun is another matter, but I'm just talking temperature.)

However, at 0F, permanent tissue damage onset is within 30 minutes, with almost any wind speed. (http://www.nws.noaa.gov/os/windchill/images/windchillchart3....)

[stephencanon]

Humans have developed clothing, which allows us to stay alive in cold weather. There’s very little we can do (short of going into a building with AC) to survive hot weather — 100 is tolerable (just), but heat gets deadly very quickly when you go above it. You don’t want to be outdoors for extended stretches in either condition (the analogy is imperfect; realistically my experience of 10F is subjectively similar to 100F, and 0F is more like 110F).

[scott_karana]

How does that change the fact that 0F is more than "uncomfortably cold" for most people?

I'm not disputing the 0F to 100F (or -18C to 40C) range in terms of being "regularly seen".

EDIT: I suppose the core of the misunderstanding is that I was addressing the "human centric" advantage and relation to brine, where you were just arguing (quite reasonably) the convenient representation of the range?

[stephencanon]

It doesn’t, but I’m being slightly approximate. Keep in mind that perception of (and physical effects of) temperature is hugely nonlinear. 0F is more dangerous than 100F, but when you go outside of that range, heat becomes far more deadly very quickly. I shovel my driveway in -20F, but I would never consider doing that sort of outdoor labor at 120F. Many people live in regions where -40F occurs from time to time, but if its 140F, you will die (actually, I think the highest recorded surface temperature is 13xF).

To your edit: yes, I think that’s the real thing. I certainly don’t think the brine thing is reasonable, just that 0-100F is a nice range.