Never, never heard of cooling blankets before today...

[Externet]

What is this ?  A marketing joke, an illusion, a trick ?  How does it work, if works at all ?

---> https://www.goodhousekeeping.com/home-products/g27471828/best-cooling-blankets/

and at many other sites 

[swansont]

Sounds like it’s a poor insulator. A blanket that doesn’t trap heat well, so you can use it when it’s not cold

[exchemist]

21 minutes ago, Externet said:

What is this ?  A marketing joke, an illusion, a trick ?  How does it work, if works at all ?

---> https://www.goodhousekeeping.com/home-products/g27471828/best-cooling-blankets/

and at many other sites 

From what I read it is designed to stop you overheating in hot weather by wicking away sweat. Do it doesn't actively cool you, it just helps avoid getting too hot and sweaty in hot conditions. Seems fairly pointless to me. You can just stick various limbs and even your torso out from the covers if it gets hot. 

[TheVat]

Yes it borders on a scam.  If it's that warm where you sleep then you would do better with just a linen sheet.  The weave of linen fibers allows heat to escape.  

When you seek knowledge, stick to the flax.

[J.C.MacSwell]

I use one. It's a poor insulator, or maybe also understood as a good conductor compared to other blankets and has a bit of weight to it. So when you cover yourself with it at room temperature it it cools you at least toward equilibrium being reached.

But the main purpose I think is having the weight of a "security" blanket without the insulation. 

I'm a baby at heart...

[swansont]

It’s like calling a cotton short-sleeve shirt a cooling shirt that you should wear when a wool sweater would make you too hot. Marketing.

But as J. C. notes, some people like the weight of a blanket. IMO it’s not any more of a scam than other advertising language is.

[mistermack]

The term "cooling blanket" is a bit scammy. But it seems to be an accepted scam, since there are so many using it, and such high prices. 

In reality, no blanket can be a "cooling blanket" unless it comes out of a fridge or freezer. Any blanket will restrict convection, and raise humidity next to the skin.  A justification might be "well, it's cooling compared to a standard blanket" which might well be true, but a truthful description would be a "less warming blanket". 

You might reasonably argue that anyone with half a brain would work that out, and that the title was just acceptable marketing hype, and the people who buy it would just expect a blanket that was less warming than an ordinary one. But I would disagree, there are plenty of people out there so gullible, that they would take it literally. 

I like something covering me, even when it's too hot at night. Hot clear nights can cool quite quickly, and you fall asleep needing nothing, but wake up cold. Also, some sort of covering might keep insects off, it's an instinct that we might be born with. An old cotton sheet is my favourite when it's hot. As cotton gets older, and more washed, it becomes more absorbent and softer. 

[swansont]

45 minutes ago, mistermack said:

In reality, no blanket can be a "cooling blanket" unless it comes out of a fridge or freezer

I saw an ad for an electric cooling blanket, which could work if it was employing peltier coolers. Also one that pumps cooled water through it.

[mistermack]

I think I'd personally opt for a bit of air conditioning, if things got so hot. Looking at the price of the ordinary cooling blankets, a powered one is likely to cross over into the price range of a portable unit. 

I just looked at one on the net, £200. It also dehumidifies, so a pretty good option for humid nights. You just need a way of venting it, they come with a long vent hose, but I guess you would need to adapt a window with the kit supplied or drill a hole in the wall. 

Evaporative coolers are even cheaper, but I've found them counter-productive for humid heat, they make matters worse. In a dry environment, they might be ok. 

AuraHome Portable Air Conditioner 9000 BTU 4-in-1 Air Conditioner, Dehumidifier, Cooling Fan with 2 Fan Speeds, Digital Display & Remote Control, 24 Hour Timer for Rooms >215ft Window Vent Hose Kit : Amazon.co.uk: Home & Kitchen  

You can also get camping AC now, that will cool a tent, so that might be a cheap option if you could make a sleeping tent indoors.

[J.C.MacSwell]

On 11/19/2023 at 6:28 PM, mistermack said:

The term "cooling blanket" is a bit scammy. But it seems to be an accepted scam, since there are so many using it, and such high prices. 

In reality, no blanket can be a "cooling blanket" unless it comes out of a fridge or freezer. Any blanket will restrict convection, and raise humidity next to the skin.  A justification might be "well, it's cooling compared to a standard blanket" which might well be true, but a truthful description would be a "less warming blanket". 

You might reasonably argue that anyone with half a brain would work that out, and that the title was just acceptable marketing hype, and the people who buy it would just expect a blanket that was less warming than an ordinary one. But I would disagree, there are plenty of people out there so gullible, that they would take it literally. 

I like something covering me, even when it's too hot at night. Hot clear nights can cool quite quickly, and you fall asleep needing nothing, but wake up cold. Also, some sort of covering might keep insects off, it's an instinct that we might be born with. An old cotton sheet is my favourite when it's hot. As cotton gets older, and more washed, it becomes more absorbent and softer. 

A room temperature blanket can be one, even if it would last longer coming out of a fridge or freezer. Unless your body temperature is room temperature...

[mistermack]

4 hours ago, J.C.MacSwell said:

A room temperature blanket can be one, even if it would last longer coming out of a fridge or freezer. Unless your body temperature is room temperature...

How? It would make you warmer than no blanket, because it would prevent convection, catch radiation and raise humidity. 

I guess you could make a case for a cooling blanket in direct sunlight, but really, it's action would be as a shade, not a blanket.

[J.C.MacSwell]

1 hour ago, mistermack said:

How? It would make you warmer than no blanket, because it would prevent convection, catch radiation and raise humidity. 

I guess you could make a case for a cooling blanket in direct sunlight, but really, it's action would be as a shade, not a blanket.

Same way a colder one would. Conduction primarily. Until at least the inside of it approaches body surface temperature it's a heat sink.

Sit on a metal chair at room temperature. It's immediately cooling in a way that a cushioned one would not be, at least not to the same extent. 

Edited November 28, 2023 by J.C.MacSwell

[mistermack]

16 minutes ago, J.C.MacSwell said:

Conduction primarily. Until at least the inside of it approaches body surface temperature it's a heat sink.

I suppose so. But to market something as a cooling blanket, that cools you for about a minute, and then warms you for 8 hours, would be stretching it a bit. 

[StringJunky]

On 11/19/2023 at 4:14 PM, TheVat said:

Yes it borders on a scam.  If it's that warm where you sleep then you would do better with just a linen sheet.  The weave of linen fibers allows heat to escape.  

When you seek knowledge, stick to the flax.

I would guess, like cotton, it is very hydrophilic. After a while you are basically covered with a damp cloth, which becomes an evaporative heat exchanger.

[TheVat]

Yup.  Linen is more absorbent than cotton and also allows more rapid evaporation of that moisture.  Linen makes a somewhat rougher weave, as it is looser woven, but the loss of smooth finish is more than compensated by its cooling qualities IMO.