To my understanding we cool off via sweat by heating up the sweat and letting it evaporate off. That system should only function based on my understanding if the air is cooler than our skin. If that is the only system in play our body temp minimum should always be the temp of the outside air, making 110F weather fatal. What am I missing here?
In: Biology
Two things.
1. Humidity. If the air is very dry, you can still use evaporation, because the air sucks up moisture from your skin. This still results in cooling, because the molecules gain energy when they become vapor. Of course, at hot enough temperatures, it doesn’t matter because the evaporation is not enough to compensate, but it can still work. This is why we speak of “dry heat” being more bearable than “muggy” heat.
2. It takes time for the body to reach critical heat overload, aka heatstroke, or just partial overload, aka heat exhaustion. This means you can survive *short-term* exposure to such weather, so long as you follow it up with seeking shelter in comfortable conditions. With the right protective clothing, access to cool water and shade, and enough breaks, you can spend most of a day in very hot weather and never suffer medical problems.
It is *possible* for humans to briefly endure even temperatures over 120°F. It’s just extremely dangerous to try if you have any other option. My city had a 114°F heatwave a couple years ago, and I survived despite not having any AC (it’s usually not needed where I live.) I just drank a lot of water, stayed inside, and kept fans and coolers pointed at me for the day.
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