A heatwave is hitting the Northeast, South and Midwest this week, making it hard to sleep due to dangerously high temperatures.
Chad Mirando, a research scientist at the Center for Climate and Health at the Boston University School of Public Health, said studies have shown that extreme heat can affect both the amount of sleep and the quality of sleep. He and other experts say the people most vulnerable to sleep loss during heatwaves are low-income families without air conditioning at home, older people, or people with underlying health conditions that make them more susceptible to heatstroke.
So as temperatures rise, it's important to have a plan for staying cool when you sleep.
How heat affects sleep
While your core temperature naturally drops while you sleep, a hot environment can prevent your body from cooling down properly, and research suggests that cooler ambient temperatures can signal to your body that it's time to rest.
A bedroom that's too hot can make it harder to fall asleep and wake you up more often during the night, said Michael Irwin, M.D., a professor of psychiatry and biobehavioral sciences at the University of California, Los Angeles. It could also make your sleep less restorative, he added.
To help regulate body temperature, the ideal bedroom temperature is between 65 and 68 degrees Fahrenheit, said Rebecca Robbins, an assistant professor of medicine in the division of sleep medicine at Harvard Medical School. Room temperatures much warmer than that could wake you up during the night, she said, especially during the stage of sleep when your body can't regulate itself.
“When we're exposed to extreme conditions, we tend to wake up shivering or waking up sweating,” Dr Robbins said.
Get ready for a good night's sleep
Experts say there's more you can do to sleep better during a heatwave than just turning on the air conditioner.
“Getting a good night's sleep starts with staying hydrated and staying cool during the day,” says Dr. Mirando. Drinking plenty of water when it's hot outside ensures your body has enough fluids to cool you down. When you're dehydrated, you sweat less and your body heats up more easily.
Experts say keeping blinds or curtains closed to block out direct sunlight can also help keep your home cool, as can keeping air circulating in your bedroom. If you don't have an air conditioner, try placing a fan in an open window to draw in cool air from outside, says Robbins.
To cool yourself down before bed, Dr. Irwin says you can place a damp rag on your forehead. “The moisture from the rag will evaporate overnight,” he says. But avoid ice packs, experts say, because holding them against your skin for long periods of time can damage the skin and cause frostbite.
Robbins suggests sleeping under a thin top sheet, which allows for better airflow and makes it easier to slide your limbs out from under the sheets if you feel too hot. Pajamas should also be thin and loose-fitting to keep heat in. But if it's really hot, “you might want to try sleeping naked,” says Robbins.
If you're having trouble sleeping during a heatwave, resist the urge to toss and turn in bed — it'll only make you feel even hotter, says Dr. Robbins.
“Try not to beat yourself up about being awake. Anyone can do it,” she says. “Get up, go to the bathroom, dim the lights, go back into the bedroom when you're tired, and get in bed when you're ready.”
