Why Humidity Makes You Sweat Like You’re in a Sauna

Stock up on popsicles, because it’s about to become hot (and humid) outside.

Why Humidity Makes You Sweat Like You’re in a Sauna

We’re in for a “hotter than average” summer, according to The Weather Channel, which means those living in high-humidity areas — e.g., Louisiana, Florida and Texas — should prepare to experience the wrath of slightly soggy Hades himself.

But why is it that moisture in the air and on our skin makes us feel hotter? Shouldn’t it have the exact opposite effect, like some kind of atmospheric super-sweat?

Because it makes no sense to us, we enlisted Kimberly Duncan of the American Association of Chemistry Teachers to give us a quick lesson on humidity and the human body. “When we sweat, that moisture absorbs heat from our skin, then evaporates [taking our body’s excess heat with it] — this is what keeps us cool,” she explains. “When it’s humid outside, however, our sweat doesn’t evaporate as quickly. As a result, the sweat can’t absorb as much heat from our skin as it normally would, so we end up feeling warmer.”

In simpler terms, moisture in the air stops your sweat from leaving your skin, screwing with your natural ability to keep cool. If the temperature outside were 75 degrees, for instance, a relative humidity of 100 percent would make it feel at least five degrees warmer.

At least there are a few things you can do to try to beat this clammy nightmare: You could wear light-colored cotton, which is nice and breathable; you could take lukewarm showers to reset your internal thermostat; or finally, you could just stay indoors till fall.

Whatever works, right?