These tried-and-true tips will help you stay cool on a hot day

Scorching. Sweltering. Broiling. The blazing hot days of summer can be described differently but they’re a shared experience across the United States—and so are desperate efforts to beat the heat. You can’t hunker down indoors indefinitely, but fortunately there are some ways to help keep cool when you venture outside on those hot days.

Take it slow, avoid overexertion, and definitely stay hydrated because sweating kickstarts your body’s natural air conditioning. Here are a few other keys to keeping cool. 

What (not) to wear during a heat wave

Less is more right?

Sundaresan Jayaraman, a professor at the Georgia Institute of Technology School of Materials Science and Engineering, says the inclination to wear less clothing when it’s hot has merit. “There’s a good reason why if you go to Costco in April you’re going to find a lot of shorts and short sleeves being put out. They are more comfortable than something covering your entire body.”

That’s fine when you can totally avoid exposure to the sun. But direct sun on skin can cause burning, or worse, and be uncomfortably hot. And tank tops just aren’t welcome everywhere.

(Extreme heat is the future. Here are 10 practical ways to manage it.)

When you need more coverage the choices are about both fit and fabric. Loose-fitting clothes are most comfortable, Jayaraman notes, because they let air circulate around the body.

The best hot weather clothing also absorbs sweat from the body like a sponge, and then evaporates it, aiding the process by which our skin cools off. And we definitely don't want clothing that sticks to our body and leave us with a "clammy" feeling.

“In terms of best fabrics to wear: Linen is certainly a preferred material,” Jayaraman notes, because of its superior ability to absorb a lot of moisture and transport it from the body without feeling damp. Linen is also permeable, letting air circulate near the body, and more rigid so it doesn’t cling to the body. (Although this comes with a tradeoff—linen wrinkles.)

Lightweight cotton is breathable and definitely absorbs moisture, but it also tends to retain that moisture and can be clammy or clinging in high heat or humidity.

Traditional polyester can be very uncomfortable because it does not absorb sweat in hot or humid conditions. But fabric science has changed the game. Ultra-fine microdenier polyester fibers commonly found in athletic wear, like Nike’s Dri-FIT, are chemically treated to wick away moisture. With these fabrics, Jayaraman adds, tightness isn’t a drawback because the fabrics are directly helping the skin’s ability to dry off and release heat. 

(Is there a better way to get rid of old clothes?)

Color is a bit more complicated. Most people know that white reflects the sun’s rays, while dark colors absorb them—and therefore believe that light-colored clothing is cooler. But white clothing also may reflect our own body heat, whereas dark fabrics can absorb it while it radiates from our bodies.

You May Also Like

ENVIRONMENT

Extreme heat is the future. Here are 10 practical ways to manage it.

SCIENCE

Are you having a ‘vampire summer’? Here’s how to make it healthy.

SCIENCE

Extreme heat can be deadly – here’s how to know if you’re at risk

This paradox means that while white clothes may sometimes help with the heat, it’s unclear whether they always have the same effect for people wearing loose-fitting clothing—as a 1980 study of bedouin robes famously revealed. Ultimately, the bigger factors in keeping you cool are fit and materials.

Sound complicated? Keep these tips in mind and then listen to your body. “If your clothing can make you feel that you have nothing on but still protects you, it is the best outfit!” Jayaraman says.

Bring your own shade

When the sun is out, simply keeping to the shade is a major key to keeping cool.

“If you are standing in the sun on a sunny day, it can make a difference of probably 30°C in terms of the heat load that hits your body, versus in the shade,” says Ariane Middel who studies urban climate and landscapes at Arizona State University and co-authored the report 50 Grades of Shade. “That’s what we measured in Phoenix but even in say Boston the difference could be 20°C.”

(Here's what extreme heat does to the body.)

Shade protects us from a heat wave double whammy: short wave radiation coming directly from sunlight, and long wave radiation coming from surfaces like pavement that heat up on hot days.

So what can you do to create shade? Trees, naturally, are renowned for providing shade but Middle says you can seek it out from buildings, walk on the shady side of the street, or even sport a wide-brimmed hat.

“All shade is great, you can never go wrong with shade,” Middel says, adding that even a typical rain umbrella works just fine in reducing the heat load on your body.

How to cool yourself down on the go

Air conditioning may not be portable, but you can improvise.

Help regulate your body’s heat by strategically cooling key pulse points like the neck, wrists, tops of the feet, and the insides of elbows and knees. An ice pack applied to these spots is like a coolant for the blood flowing close to the surfaces, which then passes through your body. “I think those cooling towels work really well, that you make wet and put over neck, those are really great,” Middel says.

And what about those carry-along fans?

 The World Health Organization and other health agencies have long warned that fans don’t do much good in temperatures above about 95°F, when a fan simply batters us with very hot air like peering into an open oven. Some research seems to bear that out, but other studies suggest that moisture may make fans useful even in very hot conditions. In humid weather, fans can drive the evaporation of sweat or other moisture on the skin to cool us down. In dry conditions, meanwhile, you could use a portable fan with an attached spray bottle to moisten the skin.

(Salted? Alkaline? Here's what you really need to stay hydrated.)

Spraying yourself with squirt misters or otherwise soaking yourself not only feels great, it works to cool you down. “Anything that involves water that can evaporate is effective, especially in dry places where air isn’t saturated with moisture,” Middel says.  

One more tip: stay cool mentally. Though those heat wave days can seem very long, cooler temps likely await when when the sun goes down. And autumn is never that far away.