How to get a good night’s sleep in hot weather – and why it’s so hard

Getting a good night’s sleep when it’s hot out can feel impossible. Unfortunately, worrying about not being well-rested doesn’t help.

Experts say worrying about sleep in warm weather will inevitably make you feel worse. “When people cannot sleep because they are too hot, it often becomes both a physical and a mental challenge,” says Dr Shelby Harris, founder and director of NY Sleep and Psychology, and author of The Women’s Guide to Overcoming Insomnia. “They may start watching the clock, worrying about how tired they will be the next day, or trying harder to force themselves to fall asleep.”

“If several hot nights occur in a row, the accumulated sleep loss can also affect mood, making people more irritable, emotionally reactive and less able to cope with everyday stressors,” Harris says.

If you’re on day three of bad sleep during a particularly heinous stretch of 100F days, here’s what experts have to say.

How does heat affect your body and brain when you’re trying to sleep?

Understanding what happens physiologically and mentally when it’s hot will give you a framework for why you’re feeling – and maybe acting – different.

“The body is constantly trying to keep its core temperature stable,” says Dr. Yi Cai, a sleep expert and the director of sleep surgery at New York-Presbyterian/Columbia University Irving Medical Center. “In hot weather, it does this by sending more blood to the skin and producing sweat, which cools the body as it evaporates. But when it’s very hot, especially if it’s also humid, those cooling systems become less effective.”

While your body is trying to cool itself down, your mind is also working overtime. “When someone is hot and struggling to sleep, frustration sets in and makes the problem worse,” says Janet Kennedy, PhD, sleep psychologist and founder of NYC Sleep Doctor. “Core body temperature naturally drops 2-3 degrees at night, which triggers melatonin production. When it’s hot, that doesn’t happen, and it becomes difficult to fall asleep.” Melatonin is released by the pineal gland when it gets dark outside and tells your brain’s hypothalamus – which controls temperature regulation, among other things – to start preparing for rest.

“Tossing and turning, catastrophizing about the next day, and worrying about not sleeping activates the sympathetic nervous system, triggering adrenaline, which heightens discomfort and keeps you awake, Kennedy says.

“If you cannot fall asleep because you are too hot, do not stay in bed becoming increasingly frustrated,” Harris says. “Get up, cool yourself down, and return to bed once you feel sleepy again.”

How can you prepare for a hot night?

Keep the sun out: The temperature outside will influence the temperature inside your home, so blocking the sun’s rays out is key. “Keep the bedroom as cool as possible,” Kennedy says. “Close the blinds during hot days to keep the sun out.”

Sleep in the coolest part of your home: If you don’t have air conditioning in your bedroom, sleep in the coolest part of your home – usually on a lower floor, says Cai, with the blinds and curtains drawn. If the temperature drops a little at night, then you can open your windows to let some of the cooler air through. “Avoid adding unnecessary heat sources like bright lights or electronics before bed,” she says.

Use the light, breathable bedsheets: For maximum comfort, sleep on the most cooling and temperature-regulating fabric possible. “Keep bedding light and breathable – cotton sheets are often more comfortable than heavy fabrics,” Cai says. Put your flannel bedsheets away for cozier times and pivot to natural materials; crisp cotton percale is a great option. Linen sheets are a great year-round choice and will keep you cool in the summer and warm enough in the winter. Other materials like bamboo, lyocell or any combination thereof can also work, but avoid cotton sateen, which is slinky, buttery, slippery and has a tight weave.

Wear breathable pajamas: Now is not the time for footie pajamas. Cai suggests loose fitting sleepwear or “as little as you’re comfortable with.”

Use cool, damp fabrics: Some of the traditional tricks for keeping cool actually do work, according to the experts. For instance, a cool, damp towel on your neck or wrists can help you feel more comfortable. Putting your pillowcase in the freezer for “a short time” before you sleep can also be pleasant, Cai says. (In my personal experience, 20 minutes should do the trick.) These temporary fixes can improve comfort, but Cai warns that “they’re not a substitute for a genuinely cool environment during extreme heat.”

Use cooling devices: Air conditioning is a straightforward way to keep the temperature of your room or home low. If you have a fan, try to maximize its effects: “A bowl of ice in front of a fan may provide some local cooling in a small space, but don’t expect it to cool an entire room,” says Cai.

Is there anything you should avoid before bedtime?

An espresso martini (or three) can feel divine in the moment, but at bedtime, you may regret your choices. “It helps to limit alcohol and caffeine, which compromise deep sleep and trigger night waking,” Kennedy says.

Heavy meals can also contribute to dehydration, Cai notes, which won’t help matters when you’re trying to get some rest. You should be drinking water when it’s hot, but don’t overdo it. “Avoid drinking large amounts [of water] right before bed if nighttime bathroom trips are an issue,” Harris says.

If you do need to hydrate before bed, Kennedy suggests a compromise: “Stay hydrated, but taper before bed. Dehydration worsens heat strain, but drinking a lot right before bed increases wake-ups.”

On hot days, it might seem sensible to save exercise and other strenuous activity for the early morning or evening hours. But morning is a better choice. “Vigorous exercise close to bedtime can increase body temperature or interfere with sleep,” Harris says.

Does heat affect some people differently?

Many of us are unhappy and grumpy in relentless heat, but it can have worse effects for specific groups of people.

“Older adults are especially vulnerable [to heat] because the body’s ability to regulate temperature becomes less efficient with age,” Harris says. Infants, young children and pets are also regularly affected by extreme temperatures. “These groups are more vulnerable to heat and may not recognise or communicate that they’re overheating,” says Cai. “Check on older neighbors regularly, encourage regular fluids, and don’t rely on thirst alone as a signal to drink.”

Tending to the people (or pets) that are most vulnerable during heatwaves requires some forethought. Cai recommends dressing babies and young children in light clothing and keeping them in the coolest rooms of the house. Pets should be walked during cooler hours, usually in the early morning or evenings, and should always have plenty of access to water and shade.

Cai also urges people to pay attention to any possible symptoms of heatstroke. “If anyone develops confusion, becomes difficult to wake, stops sweating despite the heat, or has a very high body temperature, seek emergency medical care immediately,” she says.

What if none of this works?

Remember that sleep will eventually come. Locking into an anxiety spiral won’t do much good, and will potentially make things worse. “Try not to fight with things you can’t control,” Kennedy says. “Getting angry, frustrated or desperate will raise your body temperature and make it harder to sleep.”