Why Do We Even Sweat, Anyways?
While unpleasant, sweating is actually an important bodily function—especially as temperatures soar.
Dolphins speak. Elephants paint. Even spiders can manage to use tools. But humans do, in the end, have an edge over animals: We’ve developed a hugely efficient way to control our body temperature. Dogs pant to cool down. Seals pee on their flippers. All we have to do is sweat.
Here’s how it works: Humans have anywhere from 1.5 million to five million sweat glands distributed all over our bodies. As our temperature rises, our nervous system gets to work, stimulating those glands to release the salt water we have in our bodies, says Sarah Everts, the Ottawa-based author of The Joy of Sweat. “Our hot skin evaporates the sweat away from our body, which whisks the heat away,” she says. “This trick—evaporative cooling—is what dogs do when they pant. They’re evaporating water off their wet tongue. We can just do it over our entire bodies.”
Not all of us sweat the same way—on a hot August afternoon, certain people will be soaked through, while others, miraculously, will appear bone-dry. Everts explains that those lucky ducks are sweating so efficiently, at exactly the right rate, that their sweat manages to evaporate instantly. It’s still unclear exactly what’s responsible; it’s most likely a mix of genetics and where you grow up. “People are born with all their sweat glands, but they only become fully active within the first couple years of your life,” she says. “Researchers wonder if your climate then helps dictate the activity of those sweat glands.”
It’s not as though humans abhor all perspiration: Sweat lodge ceremonies are common around the world, and it can feel like a workout barely counts if we don’t break a sweat. “But then we spend $75 billion a year on products trying to pretend we don’t sweat at all,” Everts says. There’s still stigma attached to a sweaty handshake or dark patches blooming under a work shirt. Enough. “Sweating is a fantastic temperature-control system and one of the things that makes us human,” Everts says. “So I think we need to stop giving sweat the side eye.”