Why we need to sweat

Hello, welcome to Record High. I’m Kate Yoder, a staff writer at Grist, and today, we’re looking at how sweating can help us cope with climate change.

It is embarrassing to be a sweaty person. I remember making my way to the podium to give a speech at my sixth-grade graduation, my feet squelching audibly in flip-flops with every step; taking a test and noticing the warped paper beneath my moist hand; standing up from a plastic chair and hoping no one noticed the sweaty butt print I left behind. So it came as a relief to learn that sweating was actually good for something. 

Once I learned that the science journalist Sarah Everts wrote a book called The Joy of Sweat, I knew that I had to talk to her. Everts makes the case that perspiration is a human superpower, a gift for enduring sweltering temperatures. “I think it’s funny that humans have this enormous taboo about a biological function that’s ultimately going to help us survive climate change,” she told me.

The science of sweat goes as follows: At the first hint of getting hot, your heart starts pumping blood toward the outskirts of your body. In tandem, sweat glands pump water — drawn from that blood — onto your skin. When those tiny beads evaporate, they move heat off the body and into the air. It’s an incredibly efficient way to cool down. The geneticist Yana Kamberov, who studies the evolution of sweat, told me that the ability to shed buckets of water is an ability as unique to humans as our oversize brains.

So why do we burn through all that water, one of life’s precious resources? To avoid getting cooked from the inside out. “Dying from a heat wave is like a horror movie with 27 endings that you can choose from,” said Camilo Mora, a climate scientist at the University of Hawaiʻi at Manoa, who has cataloged 27 different ways that heat can lead to organ failure and death. 

The thing is, sweating has its limits, as I reported for Grist this week. Very hot, humid conditions can render it ineffective. When the air is thic