In case you haven’t noticed—or if you live in the Southern Hemisphere or a more moderate clime—summer is upon us. Sarah Brink, writing for National Geographic:
From Arizona to Montana, from the Great Lakes to Maine, people are hearing heat advisories and warnings.
They do well to heed those warnings, says Claude Piantadosi, director of the Duke Center for Hyperbaric Medicine and Environmental Physiology in Durham, North Carolina. Human beings aren’t built to spend long periods of time in temperatures that top the body’s own approximate 98.6 degrees.
While 100˚ F feels like an arbitrarily notable number—triple digits—its proximity to our own body temperature is what really makes us pay attention, even if subconsciously. Under cooler temperatures, our bodies can radiate heat into the environment. Above 100˚ F, though, we run the risk of the opposite happening, raising our core temperature to dangerous levels. Any body temperature above 104˚ F is cause for concern.
Sweating can alleviate some of those concerns, but only as long as the atmosphere can absorb our sweat. In high humidity conditions, like those that people in the southern U.S. are used to experiencing, sweat doesn’t evaporate so much as pool on our skin where it doesn’t do much good.
In hotter, drier regions, sweat works fantastically well at keeping the body cool, even as temperatures crest 100˚ F. But there’s a hitch—sweating only works as long as your body has enough water and salt to produce it. The lesson? Stay hydrated by drinking up to 2 quarts of water per hour, and if it’s humid out, sit out in the breeze or in front of a fan. Your organs will thank you.