Here in India, when I was growing up it was normal to sleep without a cover in the summer (no ACs back then, only ceiling fans and perhaps an evaporation cooler in more luxurious circumstances). I remember when a friend and his cousin from Thailand was visiting and the power had just gone out. The temperature was in the early 40s (Celsius) but the Thai cousin who wanted to take a nap insisted on a thin cotton sheet as a cover. My friend and I were confused and kept telling him it's not a good idea but he couldn't fall asleep without it.

Speaking personally, I have the "must be covered" gene along with the "overheats easily at night" gene, so it's been a bit of a struggle hitting a balance. Right now a thin breathable quilt is the way to go, even in deep winter. Hard to explain really, but I feel anxious (and cold!) if my body is exposed, even if it's actually pretty hot in the room.

The best mitigation for this conflict seems to be those knitted blankets with the enormous holes. Terrible heat retention, and they're pretty heavy. That got the job done during a Texas summer on more than one occasion.

I'm born and raised in Sweden, now live in Spain, cannot fall asleep unless I have something covering me, but I can also not fall asleep while sweating... So in the hottest months (July and August), I tend to just use a bed sheet as the cover, does the trick.

It is a thing and not only in U.S. I live in Greece and my girlfriend can’t sleep if she’s not covered by something even if it’s in the middle of August and it’s scorching Earth outside. She says she feels vulnerable without a cover. I on the other hand can’t sleep with a cover during summer.

Yes, it is totally a thing. We don't have a lot of hot nights in Denmark but when we do, we still sleep under a duvet, or maybe half under one and it is just as awful as it sounds.

Are you sure? That seems like the sort of thing people might just not do. It can't take that many brain cells for an uncomfrotably warm person to work out that more blankets make you more hotter -> less blankets makes you less hotter.

The article seems to provide very limited evidence that people sleep under blankets on hot nights and it sounds like a silly thing to do in the abstract. A lot of people would just remove the blanket when they get hot.

Sleeping with blankets is very comfortable. If the comfort outweighs the discomfort from being mildly hot, it makes sense. Personally I just run fans and/or AC such that I am still comfortable under my blanket, because the price I pay for electricity is worth far less to me than the comfort of sleeping with a blanket.

I didn’t say we use more blankets when it’s hot.

But if you are so used to blankets that you can’t fall asleep without one, dropping the blanket because it’s hot is a pretty bad sleeping strategy

I sleep with a blanket even when it's too hot. 90% of the year the temperature is low enough that I need it, and sleeping without it the other 10% of the year just feels wrong, and I feel exposed.

I cannot sleep without a proper blanket as “protective layer”, even when it’s hot. Anecdata from Germany.

As someone who lives in the Northeast US but travels to Florida somewhat regularly it amazes me how low people keep the AC. It’s common for people and places, or at least those I visit, to keep the AC lower than I keep my heat in the winter(18c). So sometimes I’m so cold I have to ask for additional blankets or bring a jacket to a place like a movie theater.

Folks in the South don't consciously realize it, but they're setting the AC low to keep it running for its dehumidification.

These are the same folks who sweaters is its 80F outside. They can handle heat.

If ACs had the ability to run as dehumidifiers in convinced the temp would rise

If it's less than 80 outside it's cold. If it's over 69 inside then it's hot and I can't sleep

-florida man

I live in Phoenix. In summer AC is set to 84F, and in winter we heat to 78F.

Humidity does a lot.

As I've posted before:

115C with 10% humidity (71.66F wet bulb) here is hot, but as long as you have water, you're better off here than in Florida with 85F at 90% humidity (87.46F wet bulb).

It’s always 20C/68F in my apartment during the summer so I sleep with blankets. I keep it that cold to control humidity.

No, I often sleep on top of my bed during the hot summer days. I also don't put myself under the blankets when I take a nap.

I don't know what TFA is talking about.

In France some people do and some people don't but it's definitely a thing

I must have my legs covered regardless of temperature, and will easily sleep naked but with legs covered. My partner must cover their shoulders at all costs, thus opting to sleep without covers except for a blanket over the upper torso.

There’s some videos out there of people in warm climates sleeping with no cover.

Humans are funky.