Why Do We Sleep Under Blankets, Even on the Hottest Nights? (2017) | Hacker News Reader

Why Do We Sleep Under Blankets, Even on the Hottest Nights? (2017)

atlasobscura.com

259 pointsDoreenMichele187 comments

>You may think it’s unnecessary to use a blanket at 10 p.m., when it’s still hot, but by 4 a.m., when it’s colder and you’re unable to shiver? You might need it.

We have a common saying for this in Turkish. When somebody feels hot and insists on sleeping without something covering them, we say something like "it snows on a sleeper at night, you better take this on you" and hand them a minimal sheet to sleep under.

Quite randomly, regarding Turkey, I just watched the movie Midnight Express. Then watched Midnight Return right after. Only because I saw someone on HN talking about how many cats there are in Istanbul, and name-dropping the movie. Now I really want to go there. Without smuggling any hash of course. Crypto hashes are okay right? ;-)

have you watched KEDi? :)

I haven't but I plan to soon. Thanks for letting me know.

Just watched KEDi on Youtube Red [1]. Made me cry. I love my cats so much but they live the best lives when they have the freedom. And I don't know how to deal with them getting sick or dying. With kids, you usually hope you are the first to go. But with pets that have shorter lives, how to cope? There is a lot of wisdom in the movie with regard to the special relationship and insight cats give us to life itself. I have such a deep respect for Turkey now, I even have new respect for Islam. Allahu akbar. May peace be with you my friend.

[1] https://www.youtube.com/watch?v=PpG0z-npFIY

Well, this is complicated. One of the linked studies shows the opposite result claimed in this article. This article says:

"About 60 to 90 minutes before a usual bedtime, the body starts losing core temperature. There’s a physiological explanation for that: when the body is heated, we feel more alert. And conversely, when the body cools down, we tend to feel sleepier. Cooler internal body temperatures are correlated with a rise in melatonin, a hormone that induces sleepiness. A bunch of doctors tested this out by making people wear skinsuits—they kind of look like cycling outfits—that dropped their body temperature just a touch, one or two degrees Fahrenheit, to see if they’d sleep better. They did."

But when I look at the linked abstract, it says:

"By employing a thermosuit to control skin temperature during nocturnal sleep, we demonstrate that induction of a mere 0.4 degrees C increase in skin temperature, whilst not altering core temperature, suppresses nocturnal wakefulness (P<0.001) and shifts sleep to deeper stages (P<0.001) in young and, especially, in elderly healthy and insomniac participants. Elderly subjects showed such a pronounced sensitivity, that the induced 0.4 degrees C increase in skin temperature was sufficient to almost double the proportion of nocturnal slow wave sleep and to decrease the probability of early morning awakening from 0.58 to 0.04. Therefore, skin warming strongly improved the two most typical age-related sleep problems; a decreased slow wave sleep and an increased risk of early morning awakening."

It's worthing noting that the abstract disagrees with the article in two main dimensions: it's only a small change in surface skin temperature, not core body temperature; and the abstract says it's a temperature increase, not a decrease.

I know I experienced the first of those quoted effects.

Every quarter I do a 1500km drive(or actually 3000km given that I drive back and forth), which is now split into two days, but that wasn't always the case - I used to regularly spend 20h+ driving.

Anyway one thing I learned from this is how to recognize if you're likely to fall asleep at the wheel soon: you get cold, even if you weren't before.

I wonder if that actually is an agreement, but the actual measurement should be difference between skin and core temperature? So either decreasing core or increasing skin both have the same effect.

Presumably, there is an optimal temperature range for sleeping, and for healthy (not young/elderly/insomniac) adults, that temperature range is slightly below their normal temperature. That corroborates Tade0's comment below - observing that starting to feel cold at the wheel means the driver is in danger of falling asleep.

I've also embarked on long (16 hours at a time) drives, and can confirm starting to feel cold means I'm starting to fall asleep. But what I do next to continue being awake is this - I turn up the A/C. When I'm freezing cold, I can't fall asleep. Similarly, when I'm sleeping at night and the blanket has been ahem, stolen, by the significant other, I wake up from being freezing cold.

So back to the seemingly contradicting data -

>increase in skin temperature... shifts sleep to deeper stages (P<0.001) in young and, especially, in elderly healthy and insomniac participants

Likely, these _ab_normal individuals are past the "comfortably cool" temperature perfect for sleeping and are instead too cold to sleep. Therefore, a thermosuit that negates that effect and brings their temperature back up to at least "comfortably cool" aids these individuals' sleep. The logic behind this also holds for the article's claim that babies (worse at thermoregulation) need more blankets.

I agree with your assessment of the research. But my point is that the linked article does not; it claims that the research used a suit which cools the participants, which is not the case. It, unfortunately, uses an incorrect understanding of the research (a cooling suit) to support a more well-established, true statement (core temperature drops around sleep).

Hmm. I see, you're quite right - they either cited the wrong skin suit study or potentially assumed not too many people will click on "They did [sleep better with cooling suits]."

It's a weight thing for me, and not a warmth thing. I crave the feeling of something on me when I'm sleeping. Probably a sense of security. I've been on the eternal hunt for something heavy weight, and low heat. Currently using 3 x varying weights of knit cotton blankets, and does the job.

Ditto. For me, it's weight.

Have you tried out weighted blankets?

I've looked at them, they are mostly made of man made materials, I don't want to sleep with. The heat is also an issue, none I've seen address this. Cotton knit seems to be the best option right now.

Just use 2 blankets, 1 light 1 heavy, if you get cold, pull the heavy blanket over. No idea why people are down to a sheet and 1 blanket as a standard now.

Read my parent comment, I have three varying sizes of knitted cotton blankets, that I layer.

Definitely. You know when you get an x-ray at the dentist and they put that lead blanket over you? I love that thing. I wonder if they make those in a king size...

Would probably weigh more than your entire bed :)

Probably! On the plus side you'll be shielded from radiation while you sleep!

But you might be exposed to lead...

Look up gravity blankets.

Also called "weighted blankets".

The rule of thumb for optimum blanket weight is 10% of body weight + 1lb.

Perhaps a "sand vest" or "hug vest"?

I came across them with this article last month: https://www.theguardian.com/world/2018/jan/20/use-of-sand-ve...

That's a real thing, and yes, they do. They're called weighted blankets and my wife has one. They're clinically shown to help with anxiety.

I recall hearing about weighted blankets used as a way to help kids with sleeping issues.

Quote from the article:

As one more example of the goodness of blankets, there has also been a decent amount of research about the calming effect of weighted blankets, which can weigh up to 30 pounds. Studies indicate that they can curb anxiety and even be used in the treatment of autism.

This triggered my memory. I heard it helped kids with Aspargers and ADHD too.

Reminds me of Thundershirts - basically vests you put on small dogs or cats - to give them a bit of compression to help them feel better.

Conversely, I prefer the lightest-weight covering possible, but I inexplicably still need something to cover me. In the summer time, I like a lightweight sheet, and will stick with that deep into the fall.

Even if temperatures do drop overnight, I like that the sheet somewhat contains my own body heat and is relatively warm inside the sheet.

Of course, in the winter time I'll upgrade to a blanket, but I try to stick to the lightest possible one.

Same here. I've lived places where it might still be 80F at midnight, but I still need a sheet.

Oh man that's my dream. Something heavy that's not hot. I get hot very easily but I love the feeling of weight. I'm not understanding what you are using. You get the weight and little heat?

If it's too hot, I use a sheet. I think the explanation is pretty simple: crawly things that may come and bite us.

How would a sheet help with that?

Dunno about crawly things, but mosquitos definitely first go for body parts not covered by sheets.

which is pretty ineffective since mosquitos are quite good at finding the body part that's uncovered. If you sleep like a cocoon and don't move i guess that works.

That's... why you sleep under a sheet... so your body parts are covered. It definitely reduces the number of bites I get.

>If you sleep like a cocoon

That's basically how I sleep, though I do move around a bit.

If only your face is uncovered, I think you are more likely to notice a mosquito, either by sound or by touch. On the other hand, mosquitoes can reach you through a net or thin sheet if it is against your skin, as I have found to my cost.

Point the fan at the uncovered part. Mosquitos tend to dislike fan airflow. Also works outdoors. The airflow also triggers your pressure sensors so spontaneous firing isn't an startling issue if the fan breeze hits something other than your head.

Obviously for use in the hot summer; also if you sleep with a fan pointed at you in Korea, you'll catch fan death and die. Cultural myths about fan death is an interesting sleep related topic. With respect to nature vs nurture, different cultures certainly do weird things such as fan death related to sleep but the vast majority cross culturally like blankets; that would imply blankets could be genetic in some weird way not merely cultural.

You would notice that there's something under the blanket, moving toward your head.

Where I live the state bird is the mosquito. Which doesn't really narrow down my state of residence LOL. Here I am daydreaming my way to sleep counting sheep and a touch/pressure sensor in my skin spontaneously fires as they sometimes randomly do, and ugh there's a mosquito or fly or whatever on me wake up and swat it. Now wrapping in a blanket means the pressure sensors saturate full on all the time so I don't startle. I suspect its worse for men with body hair. Randomly a leg hair catches airflow and red alert a bug has landed on me! Its the same as the tickle reflex, leaning on me while cuddling on the couch is comfy and sleep inducing, tickling is not even remotely sleep inducing.

Speaking of pressure, I sleep on my side with my legs partially up and if I force myself to sleep otherwise, I wake up in that position, so may as well give in. So... maybe TMI but without squooshing at least a thin blanket between my legs there's kind of a self inflicted thigh-vise on my male parts which as any male will attest is uncomfortable. This is a universal problem for males who lift weights and sleep on their side, unless you guys have invented an interesting hack for this problem...

I would hypothesize that a cover would restrict air flow around your sweat glands which would reduce your scent on the air around where you're sleeping. It would also mask the outline of your body. For insects adapted to bite humans, hiding these signals and providing a physical barrier would possibly reduce bite incidents. Reducing bites from potentially pathogen-spreading insects would have an evolutionary advantage.

If it's friggin' HOT, and as long as there's privacy in my own room, nothin', and nada, no need for close proximity insulation technology, and for bugs? I use my mosquito bed net I bought from Amazon.

Blankets and sheets also protect from ghost, witches, monsters from under the bed... ask any child, if you're under something that hides you (or that you cant't look at), automatically you won't be found. Things that you can't look at can't look at you, too.

There's also the unspoken rule that hanging a foot or hand over the edge of the mattress fair game for Monsters Under the Bed.

I wonder if that common anxiety is the distant echo of an ancestor who slept in trees—don’t dangle, lest you get pulled to your doom by a hungry “monster”.

> Things that you can't look at can't look at you, too.

This is why, as every seasoned hitchhiker knows, always travel with a towel.

That or your Peril Sensitive Sunglasses

Towels are also good for teething (https://espngrantland.files.wordpress.com/2015/03/jerry-tark...)

A CPAP doubles as an ideal monster snorkel.

A sheet over the head also protects against killer robots, as it interferes with face recognition. It also protects against alien abductors, as their paralysis-ray guns can't penetrate fabric with sufficiently high thread counts.

These days, I mainly protect myself from the spouse's dreaded fan, that constantly blows the icy breath of Borealis across the bed. But it's nice to be safe from all the monsters, too.

In all seriousness, they protect from anything hunting via heat. Snakes and a great many insects wont notice a warm body covering in an insulating blanket as they would bare flesh.

Is the temperature of the blanket or sheet, under which I'd be sweating profusely for 8 hours, meaningfully less than the temperature of my bare flesh without the covering?

My metabolism is still producing the same amount of heat energy, and my radiant surface area doesn't increase much. If anything, the efficiency of convective and evaporative cooling drops significantly when I cover myself, so you'd think that the blanket would give off a stronger heat signature.

Thoughts?

Could be wrong about how this works, but... if it was true that a person under blankets radiates about as much heat as a bare body, that would mean blankets aren’t very good at keeping us warm.

(But they do keep us warm)

I borrowed a FLIR to check my house insulation, inevitably screwing around will happen. Also images.google.com is full of FLIR people pix. In summary the outside of clothing is much colder than skin, surely blankets are similar.

In terms of the "hunting snake theory", perhaps it's a radiation-vs-convection thing?

Supposing your body has the same amount of waste-heat per second and the whole system has reached a steady state, perhaps less of it would be leaving as infrared light (detectable by some snakes' "pit organ") and a greater proportion would be leaving via the upward rise of warmed air.

From the comments here, it seems few people read the article. This one is worth it; informative and well well written.

Most people don't read the article. They don't even finish reading the title and are already typing "Heeeey, I don't".

... are already typing "First post!" (oops, I'm in the wrong place).

I read the article and thought it was generally vapid.

People sleep in different ways. Here are some pictures of things related to sleep. Sleep is poorly studied we should study it more.

The thermoregulation and serotonin studies were helpful.

I don’t read a lot of articles because I can get an informative gist of an article quickly through reading comments. But I also rarely vote articles up or comments up for this reason

I'm not reading it because I don't sleep under a blanket on the hottest nights - can't relate.

I provide an explanation for why I'm not reading it, and you vote me down. Remarkable.

It's very healthy to read things we don't relate to. This is sometimes referred to as "learning".

You're going to learn from something based on a false premise?

"I read the article and thought it was generally vapid." -- somewhere above. Learning. Feels like I'm on Limitless.

Since you are new to HN, you may not know this, but it is considered poor form to complain about being downvoted. And more often than not, it invites even more downvotes as a result.

From the HN Guidelines (which I recommend reading):

> Please don't comment about the voting on comments. It never does any good, and it makes boring reading.

https://news.ycombinator.com/newsguidelines.html

If it bothers you this much, you're better off deleting your comment.

Offshoot question that’s always bothered me. How did ancient humans sleep before pillows?

I can’t image finding a comfortable sleeping position on a bare floor with no pillow. But other animals like dogs seem fine.

I sleep without a pillow and have for years. It can be done.

I'm in a pillow dilemma right now and have been wondering about this in the back of my mind for weeks - what position do you sleep in?

I prefer the 'savasana' position, I actually find it more confortable without a pillow in this position, I can also be by the sides or any other position, just not for all night long, I found it actually decreased upper back and neck pains after I removed the pillow

I sleep on my side with my head on my arm.

Before going pillowless, I had a buckwheat pillow. It is less cushy and fluffy than standard Western pillows. I believe they are typical in Japan and not hard to find these days. It helped wean me off the giant fluffy Western pillows.

I have respiratory problems. I sleep better without breathing in allergens and dust mites and god knows what from a pillow. Though it did take a bit of time to get used to doing it differently from how I had my whole life.

Lay on your back.

No, lay on your stomach.

No, lay on your right side.

I do all of these things throughout the night!

I read somewhere that we might have slept like orangutans [1] do.

[1]: http://l7.alamy.com/zooms/cbd59529ce184feba45db6c513db67f8/a...

I dozed off last night without a pillow and woke up in that position. Probably a "primate thing".

It's all about what you're used to.

For a year or two I didn't sleep with a pillow, I can't remember why I stopped using one or why I started again. I was still sleeping on a mattress though. I just used my arm as a pillow.

When I'm hiking, I'm sleeping on the ground without a pillow, and I've never had a problem with it.

On the flip side, I always need an inflatable pillow or a pillow section built into my inflatable mattress when I'm camping, otherwise I need to sleep on my backpack or a pile of clothes or something. Can't sleep without a pillow for the life of me.

A pillow could be a pile of softish branches with leaves.

When I camp I have to put my backpack somewhere, may as well be under my head. "naked and alone" TV show is not terribly historically accurate, surely humanoids have always a bag of something or a rolled up something to rest their head on. Alternately my wife can sleep on my arm and with some work to get my arm position right the blood flow is not cut off; theoretically a household of humanoids could sleep in a line, with the unfortunate one on the end being one of those back sleepers. Interesting bonus is if someone wakes up from hearing a tiger approach statistically half the tribe is awakened automatically for free, silently. Interesting problem is one member wants to roll over or use the bathroom at night and everyone is unhappy.

A few decades back I visited a traditional zulu village museum. In the wattle and daub huts they had thin logs for pillows, somewhat like firewood. Couldn't find an image in a quick web search.

My dad and his army unit would sleep under wet bath towels in the sweltering El Paso summer nights, in the late 1960s. He would wake up in the middle of the night, when the towel dried up and stopped cooling with evaporation, and have to go get it wet again.

It seems like an evolved reaction - make sure we are under cover, out of sight while sleeping and helpless. But given how much we move around, snore, talk, and make commotion while sleeping, having a simple cover may not help much. Maybe it was evolved for a smaller frame?

Wet bath towel sounds...horrible! Wouldn't you develop something like 'trench foot' after a while from being constantly wet?

I have definitely used a damp sheet and a small fan to keep cool on very hot nights. Idk about a towel - but the damp sheet felt great. When it's that hot you're already laying there soaked in sweat.

No, "can occur in temperatures up to 16° Celsius (about 60° Fahrenheit) and within as little as 13 hours" https://en.m.wikipedia.org/wiki/Trench_foot

It's caused in large part by reduced blood flow to the extremities due to the cold. If you are useing damp cloth to keep cool then you will have plenty of blood flow. Unsanitary conditions do make increase the risks.

I don't think they meant trench foot per se. If you lie in a bath, your wet skin goes soft and is relatively easily rubbed/peeled away around the extremities (toes, fingers).

I've noticed similar softening when walking with sweat/rain-soaked socks. Also assumed it was the condition people talk of which makes keeping feet dry on jungle expeditions so important.

Got it, however tap water is far more sanitary than jungle water, also walking around is going put a lot more stress on your skin than sleeping. Also, there is a difference from having a damp cloth on you and having water sloshing though your boots.

Historically the only option was to be constantly setting though a heat wave for days at a time. Though drying sweat leaves behind a lot of salt which does help simply being a little damp is not a huge deal.

When it’s hot, life is always better if it’s not also humid!

That's because evaporative cooling works when it is not too humid.

I guess I'm one of those weirdos that doesn't. I get hot really easily, so unless the sheets are really light cotton, I roast. Oddly enough, though, I love heated mattress pads. I can crank it up to 10 and sleep without sheets just fine.

Something relevant: does anybody have suggestions for weighted blankets? My SO is into big, heavy comforters and other bed coverings (no idea what they're called) and she'd probably enjoy that.

duvet cover?

No, actually weighted like this [1], literally 20 lb blanket. (Just an example, not a recommendation.)

[1]: https://www.amazon.com/gp/aw/d/B073451HTY/ref=psdcmw_3732181...

Weighted blankets sound interesting, I'm also interested. Personally, I love sleeping under heavy blankets, but my room has to be ~55 F in order for it to work, otherwise I'll roast and wake up super dehydrated.

Hospital blankets must be made from lead, but I don't know where they get them. Quilts are usually pretty dense.

I have this argument with my wife: in the winter we have a very nice down comforter. It is plenty warm on its own. She likes to through a heavy quilt we have on top of that. I say that it makes the bed colder... the quilt compresses the down in the comforter and it loses much of its insulation ability that way, more than the insulation added by the quilt on top. She refuses to accept this argument and says it's warmer with the comforter plus the quilt. I haven't wanted to win the argument badly enough to start taking measurements, but as a compromise, we've worked out having her double up the quilt on her side.

A long time ago they may have been made out of thick wool. I don't know if you've ever heard of or slept under a "military blanket" of the wool variety, but they're incredibly heavy and warm for their relative thickness.

My partner made me a 15 pound weighted blanket for Christmas and I love it. It's very cozy and feels nice. She made it out of light materials so it can breathe and be used in the Summer.

Cool (in the summer, I hope)! What kind of batting did they use for weighting?

She didn't get the weight from the batting, it doesn't add enough.

She used weighted plastic pellets (like beads). As she added the batting, she would sew in pockets throughout the blanket and add in the pellets in a precisely measured way so that it would be evenly distributed.

Interesting! Thanks for sharing the details!

Look for crocheted "afghans". They're very heavy relative to their warmth.

I`m a hot sleeper as well, but you'll find that ambient temperature has a profound impact. I actually sleep more soundly with a sheet + (very) light comforter at about 17 degrees celsius or lower, having read that cool temperatures such as those are best conducive to quality sleep.. this is only true with adequate bedding, though that detail is often omitted.

In the summer, without AC, I can only sleep with a single sheet barely covering me. But the quality of sleep is noticeably lacking unless I'm particularly lucky. This is because, in environments that aren't super-well climatized like modern high-rise condos, temperature may swing and fluctuate a lot, so reaching thermoneutrality (the correct amount of covering on you) can be difficult, particularly with just a sheet in my experience.

Do we?

I sleep under just a thin sheet when it's warm, and above a certain temperature I definitely prefer nothing at all.

But there is certainly something comforting about the weight of a heavy blanket, that much is true.

I definitely don’t. I live in a moderate climate and I’m under a blanket/sheet of any kind maybe 9 months a year.

I definitely do. I live in Atlanta and regardless of weather I can't sleep all the way through the night if I don't at least have a comforter on the bed when I go to sleep.

It’s an interesting question, and could have imagined people sharing their beds with pets, but with livestock? Is funny.

I personally have sleeping problems in rooms that are too warm, and warm blankets don't help. It's not when going to bed but a few hours in - around REM time? I wake up panicking as if I'm suffocating. That's why I always sleep with the window open, also when it freezes on the winter. My SO is not so much a fan :).

Oh god, I'm not the only one who has this? I had trouble sleeping in a room my parents made for me and they wouldn't believe me when I said the room is too hot. If it's like 74F or above or so I can't sleep and I'll just continually wake up with that suffocating feeling.

Is there a name for this? It doesn't seem normal and I'm dreading it come summer in a city with no AC...

Damn, my wife is like that. I'm always cold, winter or summer. But i hate heavy bedding, and prefer light sheets and down comforters. But then, for many years, I slept in a nylon sleeping bag on a foam pad.

Got hit with an unexpected blizzard once when I was on an FTX in Colorado, in December. Pure freaking misery (slept in a mummy bag with a watch cap on). Never been so cold in my life, before or since. My right foot still starts to ache whenever I get cold.

So, I live in Florida now. Usually sleep with just a sheet, until my wife steals it at 3AM and wraps it around herself 5 times so I can't get it back.

I had a Goretex bivvy bag for sleeping outside. And I carried both polyester and goose down bags, and a boiled wool blanket. So I was well prepared.

I also have trouble sleeping with closed windows, especially when it's colder outside. It's really nice to cuddle up under a heavy warm blanket when it's a bit colder in the room, tho it can make getting up in the morning a real pita when the room cooled out way too much.

I wonder if the "suffocating feeling" without an open window might be the result of higher CO2 concentration in the bedroom if it isn't aired regularly enough? Might be worse for smaller rooms without proper ventilation and more noticeable due to the sleeping position being lower than regular standing/sitting? There's also this old trope of plants in the bedroom supposedly being a very bad thing.

This seems to nail it: http://highlysensitiveperson.net/episode2/

I love having a nice thick blanket, and a cold bedroom. If I get warm I stick my leg out :D

That trick never works for me. Fortunately I have a balcony door nearby and just cool down the room some more if I need to.

I don't. Currently I have really effective heating and cooling in my apartment, that I am not billed separately for, so the temperature is pretty close to 70F (21C) all the time (the apartment management has even exhorted people to keep the heat turned up in the winter so pipes don't freeze).

I don't feel comfortable (and sometimes feel cold) unless I am under a flat sheet, but I haven't used a blanket in years.

The only way I would ever use a blanket is if the room temperature was significantly below 68F (20C) but even if I preferred that, it's not allowed due to the risk of causing a flood.

Amazes me that nobody seems to have noted (so far) that making a bed/sleeping nest is common behaviour among all the great apes. e.g. Mountain Gorillas make an elaborate (fresh) nest each night, covering themselves with some of the bedding preparatory to sleep. So why would humans be an exception?

There seems to me to be something much more deeply wired in us than has so far been suggested.

It's currently summer where I live and my wife has been sleeping upstairs at our room with two freaking blankets (one of them pretty heavy). Since NYE I have been sleeping at the ground level of the house where it's cooler, practically naked every night, desperate to be able to sleep without sweating profusely. I guess my wife really likes her serotonin bump.

Come to Hawaii in the summer. Not in a hotel, just in a normal apartment like a normal person. You'll ditch any covers whatsoever.

I used to live in the Philippines with no AC and even then, except for the hottest nights, we slept with light sheets/blankets on. Sometimes with the fan blowing under the blanket on hot nights.

> except for the hottest nights

Fewer than once a month.

Does it regularly get above 90f with high humidity or above 100f and a dry heat? Because in both those situations I still cover up.

Yes.

Anecdotally, when camping I often wake up shortly before dawn when temperatures have dropped.

I imagine that poor thermal regulation and lower serotonin in the early morning is partly the reason for waking up early. I wonder if this is a hold over from our early days as a species; as hunter gatherers it would be advantageous to be up and awake before it's light out.

People have even invented special fans for people who want to sleep under covers on hot days.

https://www.today.com/video/fan-designed-to-blow-cool-air-be...

Let's skip the news spam. Link to Kickstarer https://www.kickstarter.com/projects/bfan/the-bfan-for-a-coo...

For me it was just a habit thing. I was used to having a blanket and felt uncomfortable without it. I realized this was silly, and made a conscious decision to try sleeping without a blanket. After a couple of nights, I got used to it, and it was not a problem.

I trained myself when sleeping on a cot to not need a blanket because it was so hot but immediately after returning to a bed I started using a blanket again. I can still sleep on a cot though with no blanket. I think you can train yourself with context to sleep with our without a blanket.

When I lived in a hotbox of an apartment with no AC, on the hottest nights, I slept naked on top of all the sheets with a fan constantly blowing air over me.

I've always preferred for the room temperature to be cold, with a bunch of heavy blankets on top of me, though.

I have zero evidence, but I think it may have to do with sense of touch. For me it's more comfortable to be in a cold room under a blanket than to lie on a bed in a warm (or even hot) room. Similarly, I'm one of many people who enjoy lying in a bathtub. It somehow feels relaxing. The touch, the pressure of warm water.

Studies on autism might shed more light. Temple Grandin even built herself a machine which would touch her from sides, the way cows are.

no mention of the (apocryphal) story of people using dogs (dingos?) to keep warm when sleeping in the australian outback, where a cold night is known as a 'five dog' night. not sure how true this is, see http://www.metaphordogs.org/Dogs/entries/threedog.html for details.

Because the author and the researchers have not tried living in the tropics near the equator before. Here in Singapore, if you don't turn on the air-con, the heat and humidity acts as a blanket. This is not an exaggeration. Most of the people I know don't use blankets unless the AC is turned on.

The fact that the temperature seldom go below 27 degrees at night also helps.

Does anyone else feel that they sleep more deeply if they have an animal curled up next to them? I have a cat, but I'm sure when I sleep with him next to me on the sofa I sleep more deeply than normal.

I always wondered if there was some sort of caveman-type response, in that we knew the animal would be more alert and would wake us up if danger came near.

Some brilliant person once pointed out that apart from temperature a sheet is like white noise for your skin, which after all is a big sensory organ. Without a blanket all the tiny hairs on your skin pick up tiny air currents or whatever energy is going on in the room unless youre covered in clothes.

I have to have a blanket, or at least long sleeves, otherwise I am greatly disturbed by my own breathing as it reflects from the wall back into me.

My partner think I'm nuts.

For me, there's a privacy dimension. I don't want people to see what I look like, or am doing, when I'm asleep, when I don't even know what that might be. Although, the privacy feeling might just be my subconscious brain's way of telling me to get a blanket.

It isn't on/off for me. Every night is a bit different, even though my thermostat has the same setting day by day. One foot uncovered. Or two. Or neither. Thick blanket, or thin, or both. Many options and throughout the night the configuration changes.

I'm the opposite -- maybe because I'm Asian in Asian country. I would rather sleep without aircond and no blanket. I don't understand why people set the room as cold as possible but sleep with the thickest blanket they can find.

It's reliable. Studies have shown cooler temperatures yield better results. Thermoneutrality when completely naked though is close to 30 degrees Celsius, so in a consistently hot climate it would make sense to have barely anything on you.

I'm reminded of why we have a need for soft, comforting things (Harlow's monkeys): https://www.youtube.com/watch?v=OrNBEhzjg8I

I think it's just comforting having warmth to doze off to. My late cat seemed to jump on the bed at my feet on all but the hottest nights.

Anyhow, just gone midnight and it's 24ºC indoors which is pretty mild for summer - doona weather!

The amount of coverage that you need may vary. Experiment and you can find the combination that will help you both fall asleep and stay ventilated during the hot nights.

I figured out I just need 3 areas to cover to feel really comfy:

- feet (socks are enough)

- lower back

- my face around the eyes

For hot sleepers, this can be immensely difficult to get right. I struggled with insomnia for months in part due to the fact that temperature fluctuated as the convecs heater sucks. Best results were to keep the room cool enough that I could sleep with a sheet and light comforter. Having the comforter "partially" covering when I felt hot doesn't work. Layering sheets doesn't work either, as by the time you've piled enough, it traps too much heat which doesn't escape.

I tell you, it's all such a head ache.

I wonder about spider bites or something. Imagine sleeping on the forest floor with no covering, ants would crawl on you and stuff. Well, at least at picnics they do. A lot of bugs are nocturnal I think.

It's not like they are small enough to fit between the blanket and you.

Mosquitos, in practice, are one of the main reasons to cover up if sleeping outside.

What about the possibility that our ancestors who slept under cover where better hidden from nocturnal predators (smell and sight) and maybe bitten by fewer pathogen-spreading insects?

I used to sleep without a blanket or sheet when I was in South India. But the weather is nice and hot, which allows me to sleep without a blanket. Not in cold places.

TL;DR:

These are the reasons

1) Various studies have indicated that sleeping with a weighted blanket can trigger an uptick in the brain’s production of serotonin 2)The other element that might explain our need for blankets is what Hoagland refers to as “pure conditioning.”

> a weighted blanket can trigger an uptick in the brain’s production of serotonin

Surely that could be a result of conditioning.

Well anti-anxiety compression vests work for cats and dogs and there's some very preliminary evidence that deep pressure touch improves subjective relaxation https://www.ncbi.nlm.nih.gov/pubmed/3688151/

This is actually the first time I've ever heard of weighed blankets. As someone with severe anxiety that's helped with a hard squeeze, I'm very interested in getting one, I just wish I could try one first.

> work for cats and dogs That could still be conditioning.

> deep pressure touch improves subjective relaxation That could still be conditioning.

I'm not saying it definitely is conditioning, but I don't see enough evidence to rule it out.

For example, these animals could associate the pressure with the warmth and comfort of being the in the womb. So in a way they've been conditioned by being in the womb. Maybe animals grown in a 'test tube' wouldn't give the same results.

I find it nearly impossible to sleep blanklet-less. I guess it's encouraging to know even the Papua New Guineans feel the same.

Ugh no.

I hate sleeping under covers, and only do it when necessary. On some days I just turn up the heat enough to be able to sleep without them.

My guess is that the warm and snug feeling of behind under a blanket evokes the womb. Same idea for white noise while sleeping.

This isn't a common myth and was addressed in tr article:

"I’m very suspicious of anyone who implies that this goes back to the feeling of being in the womb,” she says. “I think that’s very far-fetched.”

Human behavior is part biologically programmed so to say that this is far fetched is to ignore evolution.

What does the concept of "retreating to the womb" have to do with evolutionary pressures?

There's a difference between the argument that people have an evolved biological preference for warmth and pressure, and the argument that this is because it evokes conditions in the womb.

Without elaboration, the latter sounds like Freudian psychobabble to me.

In Australia there's a specific phrase, "top of the bed night".

It's self explanatory. And these nights happen all summer.

In Sydney 30 degree C nights? No blankie.

Yep if it's >25C no blanket for me, especially on humid days (e.g. in Brisbane).

I didn’t read th article but from what I understand the need for cover comes from the time we are infants, where swaddling and being covered feels secure and comforting. I think the need for a cover is carried all the way through adulthood as an ingrained means of protection of outside elements.

Perhaps you should have read the article:

> If you Google around for this question, you’ll end up with a bunch of theories about blankets simulating the warm, enclosed feeling we had in the womb. There could be some element of theoretical protection or security imbued by the blanket, which might be another bit of conditioning, but Hoagland thinks the womb comparison is pretty unlikely. “I’m very suspicious of anyone who implies that this goes back to the feeling of being in the womb,” she says. “I think that’s very far-fetched.”

“I think that’s very far-fetched.” She thinks wrong. I don't see why her unsubstantiated opinion is different than anyone elses.

Because there are mosquitos, otherwise I wouldn't sleep under blankets

In Sicily during summertime definitely no blankets...

I don't, until the mosquitoes come feasting.

Do people really sleep under blankets on nights >20C? I don't, despite the 'history of bedding'.

A thin sheet sometimes, yes. Mostly for comfort though, as I can go without.

Personally, I have trouble falling asleep without at least a light bed sheet.

> 40°C , still sleep under a cover

I'll sleep with a very light sheet up to around 25c.

I keep my house at around 22c during the Winter. I'll match a light sheet with a light blanket at that point as it gets chillier randomly during the season.

I dislike air currents flowing across my skin while I'm trying to sleep, unless it's crazy hot (the central air system moving air around is enough to annoy me while I'm trying to sleep, without a cover).

I do. When I fall asleep in front of the TV (my bedroom is normally colder) without a blanket I wake up freezing. Even in summer nights I prefer a very light blanket to cover myself.

"We" don't.

All that to show an affiliate link to a blanket company at the end?

I need something covering me. I’m sure it’s a culture/childhood thing to an extent, but I can’t sleep without a layer. It’s another reason why I always wear shorts and a t-shirt to bed too (plus I can’t stand the idea of making my sheets filthy even more quickly by wearing less).

I’m the same. It doesn’t need to be heavy. During the summer it’s often simply a top sheet. But without it I find it really difficult to sleep.

I cannot sleep with any layer, very uncomfortable indeed. To be honest, I cannot stand the idea of getting irritated by clothing during my sleep. Not only that, even the faintest bit of light or even the slightest periodic ticking of the clock (or anything for that matter) annoys me. A thin blanket will do in the summer, but usually tucked to the side when hot, and a second blanket of the same material in the winter, a third blanket of the same material as a bed sheet. Everything needs to be dead quiet and super dark when I'm sleeping. I'm trying to achieve the darkness to the point where the capability of the human eye adaptation to low-level ambient light won't matter (absolute pitch black).

I found the serotonin thing very interesting. I regularly wake up at night with new very negative interpretations about social interactions and intentions. I've wondered where those ideas come from. Maybe the super low serotonin levels provide this misery for me.

There's such things as "weighted blankets." Maybe try? Not endorsing or recommending. I've never tried, probably never will. Just an FYI.

As we’re seeing here, we don’t always. Taking the premise as true though, maybe it’s modesty, or a way to normalize temperature fluctuations? From my experience in the Phillipines though, I’m with the rest here who are denying the premise of the article.

Plus no sheets means no anti-monster force fields.

In my childhood blankets were the bests against monsters. And burglars. Totally agree.

tlnr: we don't know but it's nice.

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