Here’s Why You Can’t Sleep When It’s So Damn Hot Outside—and What to Do About It

If you’ve been wondering whether it’s hot lately or just you, the meteorological reports don’t lie: This summer has been a scorcher for most of the U.S., putting millions of people in danger of things like heat stroke and heat exhaustion.

Extreme heat affects almost every aspect of our lives—including how we work, exercise, and yes, how we sleep. In fact, figuring out how to sleep when it’s hot outside is somewhat of an art form, and one that may seem lost amid the climbing temps.

An ideal sleeping temperature typically sits between 65 and 68 degrees Fahrenheit, per the Centers for Disease Control and Prevention (CDC), but that may be difficult to achieve in a home without air conditioning or that struggles to stay cool. (After all, about 10 percent of U.S. homes in 2020 did not have AC, per the World Economic Forum.)

Whether you’re sweating in your sleep or are simply too hot to drift off, sleeping in the summertime can feel nearly impossible. But there are still ways to get quality shut-eye in the midst of a heat wave. Experts like Jenie George, MD, an assistant professor of sleep medicine at the University of Pennsylvania’s School of Medicine, note one thing is key: having a plan before your head hits the pillow. “Having a routine and having these habits in place just ensures success,” she adds.

Read on to learn how heat affects our sleeping patterns and how to get better zzzs even when it’s boiling outside.

Why it’s harder to sleep when it’s hot

Heat waves in the U.S. have gotten worse over time, with more lasting longer than average each year, according to the Environmental Protection Agency. This summer, record-breaking heat swept across many American cities, with temps reaching into the 120s (yes, that’s degrees Fahrenheit) in places like Palm Springs, California and Las Vegas, Nevada, per an Axios report. As of August 9, more than 59 million Americans, about 18 percent of the population, were estimated to live in areas exposed to dangerous levels of heat, per The New York Times.

Sleeping in the heat is difficult for most humans because of our circadian rhythm—i.e., our body’s natural clock. This rhythm helps regulate how we fall asleep and wake up, our energy levels, and our body temperature, per the National Library of Medicine. At night, our natural body temp cools down, preparing us for sleep. But if our external temperature is out of alignment with our internal temperature, that can obstruct our ability to rest, Dr. George says.

“Our body temperatures start to cool down as we’re trying to sleep and they continue to cool down until the lowest point early in the morning,” says Dr. George. “If the external environment doesn’t match up with that, then it leads to disruption. That’s usually why we want it to be cooler.”

While one night of heat-induced fitful sleep doesn’t mean you have insomnia, Dr. George notes that multiple nights in a row of interrupted sleep can contribute to other health complications down the road—like high blood pressure, heart disease, or depression, per the National Heart, Lung, and Blood Institute. The general recommendation for adults is to aim for seven to nine hours of sleep each night, per the CDC, but even seven hours of low-quality sleep can leave you irritable and tired, Dr. George notes.

7 tips for how to sleep when it’s hot outside

Sleeping when it’s hot outside doesn’t always require a new AC unit or other fancy products. Here are some top tips from Dr. George to help you cool off and ultimately drift off, even amid scorching outdoor temps.

1. Let the cool air flow

Even if you don’t have central AC or a window unit, opening up the windows can be a good way to let the flow of air in. Standing fans or mounted fans can also allow for a breeze, lowering the general room temperature.

One tip: Try placing a standing fan in front of your window to help encourage the flow of air throughout the room. And if poor air quality or wildfires are concerns in your area, it may be worth investing in an air purifier to keep things fresh.

2. Take a cool bath before bed

Taking a bath is already a great way to wind down and relax before bedtime, but it’s also a helpful way to signal to your body that it’s time to sleep. Taking a cool or lukewarm bath, in particular, can lower your internal body temperature and start the biological process that leads to a restful night. A cool shower might work in a similar fashion.

3. Avoid activities that could raise your temperature before bed

This may be difficult advice to follow in the summer, especially when the ideal time to workout or walk outdoors is right before sunset. But Dr. George recommends avoiding activities that could raise your body temperature right before bed and hinder your ability to sleep shortly thereafter. If you still plan on an evening workout session, taking that cool bath after might come in handy.

4. Avoid substances that could reduce your sleep quality, like alcohol and caffeine

Splitting a bottle of wine with friends or having a coffee after dinner may sound like an enjoyable night, but it could backfire if you’re hoping to fall asleep not long after. Both alcohol and caffeine can fragment your sleep, preventing you from reaching its deepest, most restorative phases, per Michigan Medicine.

“It’s just another thing that would contribute to you waking up if it’s already warm,” Dr. George says. “This is just one less factor.”

5. Chill your socks

We know this may sound odd, but making sure your feet are not too hot could actually affect your entire body temperature, too. One tip that people swear by is chilling their socks in the fridge shortly before going to bed and wearing them to sleep, per the BBC. Others have found that wearing wet socks to bed can have the same overall cooling effect when it’s just too hot to sleep, per NPR.

6. When in doubt, think: “like a cave”

“One description I’ve always heard, even when I was learning about sleep, is to keep your room like a cave,” Dr. George says. “When I talk to patients, I say: keep it dark, keep it quiet, keep it cool.”

To her, this means making sure there is not a lot of light in the room, reducing the amount of inside and outside noise exposure, and adjusting bedding and clothing to ensure they are light and breathable (hello, cooling pajamas).

7. Set a routine

Consistency is also a key factor to a successful nighttime routine, Dr. George says. Your body becomes better acquainted with a rhythm when you’re falling asleep around the same time every night—that helps your entire biological clock understand it’s time to prepare for bed.

Engaging in relaxing activities before bed, like reading a book, meditating, or doing your skin care, can also be part of a bedtime routine that helps your body and mind prepare for sleep.

When to see a doctor about sleep issues

Tried all of these suggestions and still feeling hot at night or can’t manage to get to sleep? The CDC advises seeing a doctor if you’re frequently having the following symptoms:

• It takes you 30 minutes or more to fall asleep
• You wake up multiple times from sleep or for long periods of time
• You take naps often
• You feel sleepy much of the time, even when it doesn’t make sense

Your doctor can request a sleep study to rule out any underlying sleep disorders that could be contributing to your nighttime issues.