The importance of being sweaty
This looks even more alarming if you factor in humidity. Human beings can tolerate heat with sweat, which evaporates and cools the skin. That is why a dry 50°C can feel less stifling than a muggy 30°C. If the wet-bulb temperature (equivalent to that recorded by a thermometer wrapped in a moist towel) exceeds 35°C, even a fit, healthy youngster lounging naked in the shade next to a fan could die in six hours.
At present, wet-bulb temperatures seldom exceed 31°C.
The first paper I ever published was on sweating. It was my entry as a medical student into dermatology, and the product of meeting Sam Shuster (the rest, as they say, is history). Sweat glands don’t get a lot of attention, but the ~3 million mini-kidneys are full of fascinating biology. Did you know you can shift more fluid through your sweat glands that you can pass urine (quite a thought, considering how many pints of beer some people can manage — and no, I do not have a reference for this factoid so readers beware……).
Anyway I think I get the idea of the wet-bulb temperature, but the above (from the Economist) should give cause for thought. Isn’t skin biology and the environment so endlessly fascinating?