I'm writing a story about furred¹ sophonts. (In this instance, humanoid, although I don't think that affects the answers.) What I want to know is, to what extent would they still "add layers" (either clothing or blankets) to keep warm (or cool)?

On the one hand, wild terrestrial mammals obviously get by without clothing, for the most part. (There are a few "exceptions", such as pigs and elephants covering themselves with dirt, but that's more for cooling, whereas I'm mainly focused on keeping warm.)

On the other hand, clothing helps humans to more readily adapt to a wide variety of climates, and we do provide blankets for e.g. horses. Also, I've read that human children have a harder time keeping warm than adults, and am wondering to what extent this applies to animals. Certainly, animals that are smaller than human children can manage just fine in some pretty extreme temperatures (e.g. arctic foxes).

What I want to know specifically is, would children of a furred sophont species need clothing or blankets to keep warm, especially when sleeping, in a 'partially'¹ climate controlled environment? Would they be too warm in anything but light clothing? Or would it not make much difference? If clothes / blankets are needed, do younger children need more supplemental insulation and/or at what age would they be able to sleep 'in the buff'?

(¹ To clarify — with apologies for possibly mucking up Justin Thyme the Second's answer — they are mammals, with the usual traits as we would define "mammal".)

(² I'm assuming that, because they are furred, they are less tolerant of drastic changes in temperature, and so they don't heat / cool their houses as much as we would so that a) it's easier to go from indoors to outdoors without putting on or taking off as much clothing, and b) they can grow thicker coats in winter without risking heat-stroke indoors. Accordingly, I am asking about indoor conditions at a temperature of around 15°C / 55°F - 60°F. Note that 'indoor' also means no snow/rain, no wind unless they create it using fans, etc. Imagine your own house, but with the heat cranked down as if you were on vacation for a few weeks.)

p.s. Ignore the classic snark answer. Obviously, they'll have something for utilitarian purposes. My question is more to what extent they can do without it, especially when they're sleeping. (If you're asleep, you don't really need pockets... and you don't really want things in pockets. Like us, they'll keep their smart phones on a nightstand.) I am focused on thermoregulation, and how it would vary by age, rather than any other useful properties of clothing.


Little ones of any species have a larger surface to volume ratio. It means that they dissipate more heat than their adult parents.

This means that they need proper shelter from adverse climate. This is why hatchlings are kept warm by their parents even though they are feathered.

A blanket would therefore be a valid protection when the temperatures are low and the physical activity equally low, which is the case when resting inside their "residential area".

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Due to the square-cube law, smaller animals have a much more difficult time keeping their body temperature up. This is true of species as a whole and of individuals within a species.

A sophont species might use tools like blankets if they have primarily single births, but sleeping in a box or fluffy bed works nearly as well. If multiple births are common, it is simpler to do like kittens and sleep in a big furry pile, which for the purposes of the square-cube law makes them a single, larger animal.

Keeping cool is much more difficult when you have fur. They would likely evolve shorter coats in warmer climates, plus they'd have a general instinct to sleep (and thus slow down their metabolism to generate less internal heat) when it was too hot out, like how most cats sleep during the day—and some tropical human cultures.

Clothes simply don't make sense for their society as a whole; you would ideally have a coat that varies on length and/or thickness with the seasons, so adding anything on top of that would be counter-productive. Clothes just for children might work, but children tend to be active enough while they're awake to not need much extra help staying warm, and would they even think of it in the first place if adults never wore clothing?

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    $\begingroup$ Arguably the reason us humans need to add heating / insulation for our animals is that we've either bred ridiculous versions and put them in the wrong climate (dogs, cats, tropical goldfish etc) and/or we've taken them out of their natural social situation where even the adults can huddle together for warmth at night (horses, dogs). However, our abilities mean we can take ourselves and our animals into climates we and they are not optimised for. $\endgroup$ – KerrAvon2055 Jun 2 at 3:25
  • $\begingroup$ @KerrAvon2055, yes, I was thinking that the reason for horse blankets in particular is probably for the reasons you mention. OTOH, a species of furred sophonts might well use clothing to extend their 'natural' range, in very much the same way us humans use clothing to do so. It's much faster to throw on a jacket than to wait for natural selection to breed for longer fur / more fat. One takes ten seconds. The other might well take ten millennia. $\endgroup$ – Matthew Jun 2 at 14:02
  • $\begingroup$ There are at least two other answers just on this site why they would wear clothing anyway besides the all-important pockets. Clothes just have too many uses (yes, including fashion) for me to consider their non-existence plausible. That said, they won't have the same level of nudity taboo that humans have. (If you've seen Zootopia, that's sort of where I'm leaning.) $\endgroup$ – Matthew Jun 2 at 14:11
  • $\begingroup$ @Matthew It's customary here to warn people about TVTropes links. $\endgroup$ – StephenS Jun 2 at 17:18


I've watched my cat since she was a kitten. She likes blankets. She likes heating pads. She likes snuggling up against a sleeping human. Despite all that fur and a higher body temperature, she likes extra heat.

And that's kinda the point. I can't speak for all furred creatures, but cats have a higher body temperature than humans — which means it's easier for her to feel chilled.

I also know this isn't an issue just for cats. Farmers and ranchers must heat and/or cover animals during cold winters and people are constantly adorning their dogs.1

Add to this the fact that clothing is used for a lot of purposes unrelated to heat and the obvious transition to using them for heat is trivial.

However, in a controlled climate? That depends on how you control the climate. The fact that you have a controlled environment means you could set the temperature such that an individual did or did not need clothing or blankets (your choice!). However...

Some will, some won't

I personally hate heat. I'll wake up when the room temperature breasts 73℉. I'm really happy when the room is 58℉–63℉. My sisters, on the other hand, are really happy to sleep in 80℉ temperatures. The answer to your question is, frankly, "obviously, yes." However, just like humanity, there will be variation amongst your fuzzy youth. Some will curl up with a thick blanket and a cup of hot cocoa and others will throw off the sheets and their clothes and wish they could shave off all their fur — all at the same temperature.

1To be fair, it's really hard to prove that dogs need extra heat. I know the Malamute Husky my family had when I was a child liked the 100W light bulb in his house during the winter, but people dress their poor, defenseless dogs for a lot of reasons that have nothing to do with heat — and yet the one nice lady I knew who did this constantly claimed it was to keep the dog warm (I happen to know that dog was sweating like the proverbial stuck pig). Anyway. Dogs. Yup.

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  • $\begingroup$ Dogs don't sweat. They do not have sweat glands. That is why they pant all the time. $\endgroup$ – Justin Thyme the Second Jun 2 at 1:52
  • $\begingroup$ Dogs are probably more representative. Cats were originally desert dwellers, so they might think 80°F is "brisk". Mine definitely like warm, but they don't give the impression, at least circa 60°F, of needing it. In fact, at 80°F they like to lay on the floor as if they're too warm. Will my sophonts appreciate warm? Almost certainly (at least some individuals, as you note!) I remain less certain that they need clothes or blankets or whatnot. $\endgroup$ – Matthew Jun 2 at 14:16
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    $\begingroup$ @Matthew: It also depends on the breed. My friends' Vizslas (high energy, very thin coat) easily get cold when they're not running, while my Plott Hound (about same size, heavier coat but nowhere near Malamute) loves to roll around in snow, and will jump into ice-rimmed ponds to chase ducks. $\endgroup$ – jamesqf Jun 2 at 16:31
  • $\begingroup$ @JustinThymetheSecond you know... your right. And yet when I've removed the pretty jumpers from overheated dogs they're invariably wet. Maybe they're taking advantage of every convenient water source to try and keep cool? Beats me. But they've always been wet. $\endgroup$ – JBH Jun 2 at 18:25
  • $\begingroup$ @Kat, You may want to carefully read a dictionary where you'll find the verb "to breast" means "to contend with resolutely" or "to confront." I would have reversed your edit. $\endgroup$ – JBH Jun 2 at 23:39

Except for people doing dangerous jobs that require protective gear, the answer for the vast majority of humans is largely a function of culture.

Furless humans can, and do, get along in a variety of environments without any clothing at all. Classic example is the Yaghan, the southernmost people in the world. They've lived in Tierra del Fuego for at least 10,000 years and have evolved some interesting physiological and practical ways to keep warm, even though they don't wear any clothing. Traditionally the men would hunt sea lions from canoes, which I suppose is dangerous enough in the cold weather, but the women were truly brave and dove into the water to collect shellfish. Water temperatures are in the forties all year.

I suspect your furred sophonts would have even less reason for wearing clothing than humans do. You don't say anything much about their evolution or environment, though I suspect that since your interest is keeping them warm, they inhabit a cool environment. Classic example of sci-fi & fantasy furred sophont is the Wookie:

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Here we see Chewbacca with Han in the undoubtedly chilly hangar in the rebel base on Hoth. The human is sporting a thick parka, heavy trousers, gloves, heavy boots, and if he weren't mugging for the camera, would probably have his hood up. The Wookie is wearing a bandolier. When in action, he also wears a crossbow. Wookies don't seem to be much into protective gear of any kind, so they're pretty much naked all the time.

Infants of your race, generally being kept close to mama, will likely be sufficiently warmed by her own body as required, but it's possible they might make some kind of warm blanket or sack to put babies in, if only for carrying them around. I don't think the children of your furred sophonts will need to wear clothing of any kind and would probably view other kids' mama's comforting blanket as something only for babies and will probably tease each other about its use without mercy.

I'd suspect that, if this race made blankets at all, they would probably be used for comfort rather than warmth. Whatever kind of shelter they live in, it will probably be floored in some way. Maybe wood or bamboo or stone. A few thick blankets will make sleeping arrangements much more comfortable!

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  • $\begingroup$ Wood, stone? Check. Bamboo? Probably, as an "eco-friendly" alternative to wood (or in cultures other than the one my story focuses on). My MC's room is deep-pile carpet, however. The setting is mostly like modern America; they have smart phones, forced air climate control, and houses that wouldn't seem (immediately) unusual if they were suddenly dropped in a modern American suburb. A somewhat more lax attitude to loose fur would be your first tip-off, but as you looked deeper, you'd find others... $\endgroup$ – Matthew Jun 2 at 14:24
  • $\begingroup$ @Matthew - Fair enough! By bamboo I wasn't referring to modern "eco friendly" fads but rather to its use as a primary functional materia, e.g. in SE Asia! $\endgroup$ – elemtilas Jun 2 at 16:12
  • $\begingroup$ Right, you were thinking of a different level of technology, or at least different cultural "norms", than I had in mind... which is fair, because I didn't specify! So I was just clarifying my intent. Related: blankets would work, but they'll stick with their memory foam mattresses, thanks 😉. Again, not saying your answer is "wrong"... $\endgroup$ – Matthew Jun 2 at 16:22
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    $\begingroup$ Conversely, I don't see them being so "clingy", but again, that's cultural, because I'm mostly copying modern Western culture where we don't carry our babies as much as. (Also because one of my settings is an orphanage which is noticeably lacking in biological mothers...) However, that's the great thing about this site; just because I might not use your ideas doesn't mean they're bad! Your spin on blanket-shaming is especially interesting. $\endgroup$ – Matthew Jun 2 at 16:27
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    $\begingroup$ @Matthew -- Right, you didn't specify, which is fine! That gives us a little more leeway to respond. My response was really geared more towards the physiological & cultural evolution of your people. And hence the different tech level you noted! That they have modern tech is all well and good, but this kind of question requires us to look back through time so we can see what physiological needs they must meet in order to merely survive and later what cultural norms they come up with that may or may not alter their natural state. $\endgroup$ – elemtilas Jun 2 at 22:24

Yes if you want them to.

No if you don't want them to.

There is absolutely no requirement for your furry sophont to be warm blooded.

Us poor humans need our blood to be a consistent temperature, and so we go to great lengths to maintain an environment that is conducive to that. If the environment is cold enough that our bodies can not maintain our preset temperature, we take measures to preserve out heat. If the environment is warmer than our body would like, we take measures to cool down. Our body, in turns out, has several mechanisms for adjusting our temperatures, from burning fat to sweat glands.

However, a being that was not warm blooded would have no absolute need to maintain a consistent temperature.

That said, I suspect the metabolism of this being would be directly related to the external temperature, as it is with most cold blooded animals, instead if being inversely related as it is in humans. When it gets cold outside, humans become more active to increase the internal temperature (shivering is a classic example) and become more lethargic when the temperature increases.Cold blooded animals, on the contrary, tend to become more lethargic the colder it gets. Given that, methinks it would be a cultural thing. Would your sophonts, should they be cold blooded, desire to raise their body temperatures in order to become more active and productive, or would they simply adjust their movements to the outside temperature?

Should you wish your sophonts to be warm blooded, there are many mechanisms you can add to their nature that would allow them to better maintain their internal temperature. Prodigious sweat glands under the fur, the ability to shiver, the ability to fluff up the fur, panting or even a radiator gland that moistened air can flow over, prodigious capillaries near the skin, so blood flow can radiate heat, 'shiver glands' inside the body that use muscle contraction to generate heat, even an 'internal furnace' organ that is essentially pure mitochondria the prime purpose of which is to convert fat to carbon dioxide, water, and heat.

So, TL:DR, a definitive answer to your question completely depends on how you design your sophonts overall, in their entirety. Careful evolutionary adaptations to their bodies can significantly alter their necessity to 'keep warm' or 'cool off'.


An interesting factoid. Human females have a thicker layer of fat just under their skin than do males. It is hypothesized that, in evolutionary terms, the females stayed back at the camp, with relatively low high-demand movement, so they needed the fat to keep them warm, but the males went out on the hunt, requiring massive outlays of power and exertion in a short time frame, so they had to get rid of massive heat loads from muscles fast. Thus, lower fat, more capillaries near the skin.

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  • $\begingroup$ Sorry, I should have clarified that they're mammals. Still, +1 for the interesting information on how they might thermoregulate. $\endgroup$ – Matthew Jun 2 at 14:18
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    $\begingroup$ There is a reason for them to be warm-blooded; large brains (as in sophonts) continually require a lot of energy, which tends to require self-thermoregulation. $\endgroup$ – prosfilaes Jun 2 at 14:36
  • $\begingroup$ @prosfilaes As long as they need to be thinking at top form all of the time. That is why I threw in the 'cultural thing' for cold blooded beings to want to keep warm all of the time. $\endgroup$ – Justin Thyme the Second Jun 2 at 14:39
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    $\begingroup$ In Canada's North, a test of a good sled dog is to leave them out in the snow in the bitter cold. Then, look at the snow pad under them. A really good sled dog will show zero snow melting. That means, they kept all of their body heat inside their body under their fur and skin. so that no heat escaped to melt the snow. $\endgroup$ – Justin Thyme the Second Jun 2 at 14:41

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