Summer Science: Clothes Keep You Cool, More Or Less

Play associated audio

The cool weather in London is good news for the Olympic athletes because their bodies won't need to put as much energy into cooling off.

But most of us aren't lucky enough to be headed to London, and we could use some help keeping cool.

When you get hot you sweat — but it's not enough to just sweat. To cool off, you need that sweat to evaporate. It's evaporation that drains the heat from your body.

To help the sweat evaporate, you want air to flow over your skin — as much of your skin as possible. So the best clothing for people to wear when exercising is none at all.

That's according to George Havenith, a professor of environmental physiology and ergonomics at Loughborough University in Leicestershire, England.

"They would probably want to wear some underwear to just cover up and be comfortable in that way. But in terms of the heat loss, the naked person is best able to lose heat."

That's only if the sun's not shining. If the sun's out, you need clothing to protect your skin from burning.

"So then you have to find a balance with a certain amount of clothing coverage," Havenith says, "without the clothing actually hampering the sweat
evaporation."

But that made me wonder. Why wear clothes? Why not just wear sunscreen?

"Unfortunately sunscreen sometimes affects sweating," Havenith said. "So the sunscreen then might reduce the amount of sweat evaporation or the amount of sweat production. So that's where things again could go wrong."

So if you're exercising in the heat, wear as little as possible, especially after the sun goes down.

But if you're not an Olympic track star, skimpy Spandex is not the way to go. Think light and loose. That's because even if you don't feel like you're sweating, you still want to evaporate moisture off your skin. The loose clothing allows air to pass long the skin and exit, speeding evaporation and carrying off excess heat.

Another big question in the summer clothing world is color: dark or light?

Researchers have studied the heavy black robes worn by Bedouins in the desert. They say the key there is thickness. The outer layer of fabric does get hotter because the black color absorbs more heat. And that heat doesn't get transmitted to the skin because of the thick fabric.

But thin black clothing transmits that heat to the skin, making a person hotter.

To sum up: Light-colored clothes in the summertime during the day, and get naked at night.

"I'll leave that to you to be said," Havenith said. "But in essence that's probably quite the basics."

Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.

NPR

'The Terror Years' Traces The Rise Of Al-Qaida And ISIS

Lawrence Wright's new book collects his essays for The New Yorker on the growth of terrorism in the Middle East, from the Sept. 11 attacks to the recent beheadings of journalists and aid workers.
NPR

Berkeley's Soda Tax Appears To Cut Consumption Of Sugary Drinks

According to a new study, the nation's first soda tax succeeded in cutting consumption of sugar-sweetened beverages. But there's uncertainty about whether the effect will be permanent.
WAMU 88.5

Questions About Hillary Clinton’s Newly Uncovered Emails

A federal judge orders a review of nearly fifteen thousand recently discovered Hillary Clinton emails from her time as Secretary of State. A new batch related to the Clinton Foundation was also released. Join us to discuss ongoing questions.

WAMU 88.5

Questions About Hillary Clinton’s Newly Uncovered Emails

A federal judge orders a review of nearly fifteen thousand recently discovered Hillary Clinton emails from her time as Secretary of State. A new batch related to the Clinton Foundation was also released. Join us to discuss ongoing questions.

Leave a Comment

Help keep the conversation civil. Please refer to our Terms of Use and Code of Conduct before posting your comments.