As human-driven climate change continues to remodel the globe, heat waves are hitting harder, longer, and more frequently. The consequences of this crisis will, on a macroscopic scale, upend where and how humans can survive. It will also, in an everyday sense, make our lives very, very sweaty.
Perspiration is vital to life. It cools our bodies and hydrates our skin; it manages our microbiome and emits chemical cues. Sweat is also a fundamental part of what makes people people. Without it, we wouldn’t be able to run long distances in high heat; we wouldn’t be able to power our big brains and bodies; we wouldn’t have colonized so much of the Earth. We may even have sweat to thank (or blame) for our skin’s nakedness, says Yana Kamberov, a sweat researcher at the University of Pennsylvania. Her team’s recent data, not yet published, suggest that as human skin evolved to produce more and more sweat glands, fur-making hair follicles disappeared to make room. Sweat is one of the “key milestones” in human evolution, argues Andrew Best, a biological anthropologist at the Massachusetts College of Liberal Arts—on par with big brains, walking upright, and the expression of culture through language and art.
