The Real Reason Humans Need To Sleep Under Blankets

If you're one of those people who just can't bear to sleep without a blanket, no matter how hot and uncomfortable it is, you're not alone. As soon as blankets and covers became available to the everyman — toward the end of the Middle Ages, when textile industries took off — we've been compelled to use them by this weird and sometimes illogical need. There's a bit of method behind the madness, though, and it all has to do with channeling your reptilian side.

There are a few things working together that feed your need for blankets. The first is a neat bit of body science. When Atlas Obscura spoke with Dr. Alice Hoagland from the Unity Sleep Disorder Center in Rochester, New York, she said it partially has to do with what happens to our bodies when we enter REM sleep. There's a lot going on while we're dreaming, and the weirdest thing of all is that our bodies completely lose the ability to regulate internal temperature.

Yep, here comes another Simplified Science Fact you were taught in high school. Humans are, for the most part, warm-blooded, but during REM sleep we have more in common with a lizard than our old friends the chimpanzees. For about four hours a night — assuming a proper night's sleep — you're relying only on your external surroundings for warmth. You're going to get cold when you're in REM sleep, and that's when you'll need the blankets.

Something else happens to you in REM sleep, and that's a decrease in your body's production of serotonin and dopamine. Those are feel-good chemicals, and let's face it, we could all use a little extra of that stuff. Can you guess what's been found to raise the levels of these happy chemicals we produce? Blankets. It's been shown in several studies, and it's the theory behind the use of weighted blankets for everything from insomnia and anxiety to autism.

(Disclaimer: We aren't responsible if you decide to start using blankets in the workplace, although we can confirm that it's awesome.)

Hoagland also said part of the reason we're so attached to our bedtime blankets is simply conditioning. We've always had blankets when we sleep, so it just feels right. It might go even deeper than that, and while she discounted nutty theories suggesting a blanket reminds of us our time in the womb, it's possible that grown-up you needs a safety blanket just like you have since you were a wee tike.

When you were little, were you afraid of the dark? You probably were — Dr. Sue Hubbard says it's one of the most common fears kids have, and since using logic and reason on a 2-year-old is about like herding a few dozen cats 'nipped up on the good stuff, it's a fear most parents have to deal with for a long time. When you were a kid, what did you do to keep the monsters away? You probably hid under your blankets because blankets are magic. The idea of blankets as protection is behind companies like Glow Away, which uses a book and blankets to empower kids against the dark. They also mention something about "magical thinking," which even many grown-ups could use more of.

So we're well-conditioned by adulthood, and the dark doesn't get any less scary as we age. All those things you forgot about during the day will just come back to haunt you. 

And anyone who claims they don't want a magic blanket to keep those thoughts away is a liar.

Many of us are so reluctant to give up our blankets, even when it's hot, that we can't just kick them off. We might stick one foot out from under the covers or wrap a leg around on top, but completely ditching the blankets is craziness.

There's a very good reason all humans do the same thing. For this one, the National Sleep Foundation's Natalie Dautovitch pointed right back to temperature regulation. There's a reason we expose our feet to the night air: feet are super-efficient at temperature regulation. Not only are the bottoms of your feet hairless but they're outfitted with structures called arteriovenous anastomoses. The same things are in our hands, and one of their purposes is to dissipate body heat. Pretty cool!

Your crazy sleep habits aren't so crazy at all, and you're actually being super-efficient without even realizing it. Good job, you well-adjusted human!