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.