Why it's important to find shade when it's hot and sunny out
When it’s hot outside, your first instinct may be to head inside — somewhere that the air-conditioning is on full blast. (Trip to the movie theater, anyone?) Sometimes, however, you’re stuck languishing in the heat. In moments like those, experts say, it’s crucial to seek out shade — and doing so can even help stop you from developing a heat-related illness.
Why does shade have such a major impact on how our bodies manage heat? Here’s what experts say, and when you have to be extra cautious about the sun’s heat.
Why does standing in the sun feel so much hotter than being in the shade?
You feel cooler standing in the shade than in direct sunlight — but in reality, the shade represents the actual air temperature outside. Direct sunlight makes the weather feel warmer, usually by up to 10 to 15 degrees.
“If you were to put a block of metal in the shade and a block of metal in the sun, the block of metal in the sun will get hotter,” Craig Crandall, an internal medicine professor at UT Southwestern who studies heat effects on the body, tells Yahoo Life. “Just like the block of metal, we too will get hotter when we’re in the direct contact with sunlight, due to what’s called ‘radiant heat.’”
How can staying out in the sun impact your health?
Here’s how it works: The sun emits radiant heat and your body absorbs it, causing your temperature to rise. To cool down, your body uses mechanisms like sweating. When the sweat evaporates from your skin, it takes the heat with it.
However, if you get too hot, your cooling mechanisms can’t keep up. This can lead to heat-related illnesses like heat exhaustion, which makes you feel weak and dizzy, and heatstroke, a serious condition where your body can no longer regulate its temperature.
Dr. Neal Patel, a family medicine physician with Providence St. Joseph Hospital in Orange County, Calif., tells Yahoo Life that spending too much time in the sun can also lead to an increased risk of sunburn, as well as a higher risk of skin cancer — particularly when people don’t use proper protections, like sunscreen or clothing that protects from the sun’s ultraviolet rays.
Patel notes that spending time in the sun can also potentially impact eye health. The UV rays from the sun — which can damage your skin — can also cause issues like cataracts and macular degeneration over time, especially if you are directly gazing at the sun without protective sunglasses.
What surfaces should you avoid on a sunny day?
Have you ever slid into your car on a sunny day, only to feel like you burned yourself on a hot leather seat? Blame radiant heat, which can cause normally safe surfaces to heat up to the point where they can cause burns.
Along with leather seats, other surfaces that can get dangerously hot when in the sun include:
Metal
Steering wheels
Playground equipment, including slides
Asphalt and concrete
Sand
Car interiors (like dashboards and seat belts)
Surface temperature is something parents should be extra cautious about, especially if they take their children to play in areas that could become dangerously hot on a sunny day, says Patel.
“Asphalt and tar can be dangerous in direct sunlight since they can heat up the floor quite a bit and cause burns if a child is to fall,” he explains. “It is OK for children to play on these types of surfaces if they have a fountain or way to cool the floor, but overall it’s important to understand the dangers that they may possess.”
In general, he says, foam surfaces found on children’s playgrounds tend to be safer than metal and plastic, since they don’t emit as much heat as the other surfaces. Parents can check to see how hot these surfaces are before allowing their children to play.
Pet parents should also be cautious, Patel says, as dogs (and other walkable creatures) may burn their paws on hot sidewalks and streets. A general rule of thumb? If the sidewalk is too hot for you to walk on barefoot, it’s also too hot for your pet.
What can you do to make your own shade?
Sometimes there isn’t natural shade in an area, and you have to make your own. Crandall says one way to do this is by bringing an umbrella with you when you know you’ll need to seek refuge from the sun. While the U.S. hasn’t quite embraced individual umbrellas for shade the way European and Asian cultures have, they’re an easy way to protect yourself from the sun.
“It’s really no different from going to a soccer game and putting up a canopy,” Crandall says. “You’ve now blocked or impeded the effect of that radiant heat directly shining on you.”
Another option: Wear a hat, which can provide a barrier against this radiant heat as well. “A wide-brimmed hat can be quite effective in creating shade,” he says.
Crandall also recommends considering the clothing you wear on sunny days. Lighter clothing will reflect the sun, he says, while darker clothing will absorb more of that light and heat. Research shows that certain colors stay cooler than others: In a 2023 study, white, yellow, gray, red and purple shirts remained the coolest, while black, blue, light green and dark green shirts absorbed the most heat.
It may be tempting to escape an extra-sunny day by sitting in your car — but if you do, keep the air conditioner running. Here’s why: When sunlight passes through the car’s windows, it heats up the surfaces within it. This causes the interior of the car to radiate heat — almost like an oven. The inside of the car will become even hotter than the outside temperature, making it very dangerous (and even deadly) for those inside. That’s why you should never leave a child or pet in a car.
While finding shade is a great way to escape the effects of the sun, sometimes it’s not enough to combat the heat. If you’re struggling to stay cool, even in a shaded place outside, it’s time to seek a cooler indoor space, such as an air-conditioned home. And if you do find yourself suffering from symptoms such as dizziness, nausea or excessive sweating, which can indicate heat illness, seek out medical attention immediately.
🌆 Heat and your health
What are the signs of heat illness? Symptoms to look out for include cramps (pain or spasms in the arms, abdomen or legs), headache, dizziness, nausea, weakness, confusion, high body temperature and seizures.
How extreme heat affects the body. Sweating is just one of the ways in which our bodies respond to heat. The groups more vulnerable to extreme heat include children, older adults and pregnant people, among others.
Stay hydrated. Keep that water bottle full, and make sure you’re not ignoring symptoms of dehydration.
Be careful around booze. It’s easy to get dehydrated when you’re drinking alcohol in the sun — which can spell disaster if you’re near water. Read this before your next pool party or lake day.
How heat affects sleep. “Research has shown that when temperatures are too hot, sleep quality and depth suffers,” says W. Christopher Winter, a neurologist and sleep medicine physician.
Eat hydrating foods. Watermelon, cucumbers, celery, strawberries, kiwi, spinach and more nutrient-dense foods with high water content are great for hot days.
How to dress when it’s hot. Airflow is crucial!
Extreme heat can affect your mental health. As your body temperature rises, your body finds ways to cool itself through processes like sweating. This uses up energy, which can make you feel more lethargic or depressed.
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