Why You Can't Sleep Without A Blanket Or Sheet, Even If It's Hot AF

Plus, advice on how to get a good night's rest when it's warm.
Janine Mclaren / EyeEm via Getty Images

Getting (and staying) asleep during oven-hot weather can sometimes feel like more work than, well, your job. You know an easy solution to staying cool and sleeping better would be to toss your covers ― yet no matter how sweaty and uncomfortable you get, you can’t bring yourself to go entirely free of a sheet or blanket.

You might drench yourself in cold water before getting underneath, or wrap one leg over the top, or blast a fan directly at your side of the bed. You might even feel brave enough to sleep with the back half of your body exposed (while your front half hangs on tight). But get rid of that top covering entirely? That’s crazy talk.

Why is sleeping without the covers such a dealbreaker, even though it could improve the quality of your sleep exponentially? Glad you asked.

Blankets and sheets are usually a handy sleep accessory ...

“Our circadian rhythm is tied to temperature, and a drop in core body temperature happens right before sleep,” explained Ellen Wermter, a board-certified family nurse practitioner in Charlottesville, Virginia, and a spokesperson for the Better Sleep Council.

Your temperature continues to fall throughout the night. It’s your body’s way of conserving energy so it can be redirected to other systems like digestion.

Sheets and blankets keep your body temp from dropping too low and waking you up, which gives your innards the chance to complete their restorative processes sans interruption.

... But during hot weather, not so much.

When it’s sweltering, our covers ritual can work against us. For one thing, even a sheet in hot weather traps the heat against your body. “When you’re already warm, it drives the temperature up further and creates an under-the-covers steam oven,” Wermter said.

Because the natural drop in body temp right before sleep is a cue that it’s time to sleep, temps that are too warm trick your brain into thinking it’s time to be active, not rest.

And even if you do manage to fall asleep, odds are you won’t stay that way. “Your core temperature is likely to rise high enough to wake you as your body works to cool itself,” Wermter said. This fragments your sleep.

Breaking up with the covers isn’t as easy as it sounds.

Much like the initial drop in body temperature is a cue for sleep, so too is pulling the covers up over your tired body. (Experts call these cues “sleep onset associations.”) “It’s part of your routine, and without it, your brain feels that something is missing and may find it difficult to relax,” Wermter said.

Plus, it’s a comfort thing.

During REM, or rapid eye movement, periods of sleep, your serotonin levels decrease. Serotonin is the neurotransmitter best known for encouraging feelings of calm, said Sanam Hafeez, a neuropsychologist and adjunct professor at New York’s Columbia University.

The use of blankets, especially weighted ones, is associated with higher levels of serotonin, meaning they can help us sleep better. It may be that the heaviness of the bedding causes deep pressure stimulation that activates the parasympathetic nervous system, potentially increasing dopamine (another mood-boosting neurotransmitter) and serotonin levels in some individuals, Wermter explained.

So if ditching the covers may, paradoxically, cause you to lose just as much sleep during hot weather as keeping it on, what’s the best course of action? Here’s how experts suggest you adjust your bedding game to stay cool, dry and well-rested.

Sofie Delauw via Getty Images

Take a hot shower before bed.

“When you rapidly heat your body in the shower, you trigger your natural thermoregulation process,” said neuroscientist Chelsie Rohrscheib, a sleep expert in Australia and member of the Sleep Cycle Institute.

In other words, the water on your skin evaporates after the shower, cooling your core down lightning-fast and telling your brain that it’s bedtime. The result? Your covers will feel more like a cozy oasis and less like a pressure cooker.

Go lighter in stages.

If going from a heavier blanket to nothing at all is too much of a jolt, gradually lighten your covers over the course of several nights.

“This gives your brain time to adjust to the weight difference as you swap your blankets out for ones that are thinner and breathe more easily,” Wermter said.

Or layer your bedding and adjust what covers you on an as-needed basis each night.

Sleep in your skivvies.

Pajamas can trap heat and be difficult to remove in the middle of the night without disrupting your sleep, Wermter said. Enter your underwear ― or even your birthday suit ― instead.

Invest in a cooling pillow.

Your brain temperature needs to drop by 1 or 2 degrees before you can fall asleep, Rohrscheib said. In hot environments, this can be a tricky feat. Cooling pillows are a convenient way to speed up the process, as well as to increase the likelihood that you’ll stay asleep.

Try a cooling weighted blanket ...

“They’re designed to keep you cool without losing the sensory benefits of a thicker weighted blanket,” Hafeez said. Made from lightweight, soft-brushed cotton sheeting, cooling weighted blankets give off that cozy flannel vibe without trapping heat.

... Or a lycra compression sheet.

These can give you the cocoon feeling you crave without the bulk and heat of a heavier blanket, according to experts.

Bamboo blankets can help too.

“Bamboo blankets are cozy, yet still move heat away from your body,” Hafeez said.

Snuggle up to a specialised body pillow.

A so-called clone pillow uses shredded memory foam and a removable cooling gel layer to keep your body from roasting, Hafeez said. It’s also covered with a cotton pillowcase, a fabric famous for allowing your skin to breathe.

Uncover your feet.

Research suggests that keeping your feet cool ― say, by sticking them in cold water before bed or poking them out from under the covers ― can help lower your overall body temperature.

Give yourself some space.

Sleeping close to your partner can amp up the heat index, Wermter said. If your mattress is big enough, give yourselves enough room to better regulate your individual body temperatures.