# Heating blankets = popular. Cooling blankets = non existent commercially. Would you buy one? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [May 4, 2010, 5:24pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302 "2010-05-04T17:24:59Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![DiosaBellissima](https://avatars.discourse-cdn.com/v4/letter/d/a8b319/32.png) [@DiosaBellissima](https://boards.straightdope.com/u/DiosaBellissima)\ **Post date:** [May 4, 2010, 5:24pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/1 "2010-05-04T17:24:59Z")
Just last night, I was laying in my bed with the windows open, fans on, thinking about how it is barely May and I am already goddamn warm while sleeping. I’m the kind of person who has to be frozen while I sleep, so I can wrap myself up in a blankie and sleep. If it is too hot while I am trying to sleep, I’ll get migraines and just can’t sleep. So, all summer my AC blows, cooling my entire house, wasting energy, etc. Now, during the winter, instead of running my heat (hey, I live in California), I use an electric warming blanket on my bed. I love it. But last night, while thinking of all of these things, I came to wonder why there isn’t a cooling equivalent of the heating blanket? It’d be a great idea- I could run my AC a little warmer, but keep my bed nice and cool. Save energy, be more comfortable, everybody is happy. The only thing I can think of is that cooling is harder than heating, so it just isn’t economical to produce such a thing. Is this on the right track? I also thought that maybe there wouldn’t be a market for such an item, hence the poll above. Of course, it’s entirely possible that there’s a whole world of such devices out there that I have stupidly overlooked. 🙂 ---
**Author:** ![Dangerosa](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Dangerosa](https://boards.straightdope.com/u/Dangerosa)\ **Post date:** [May 4, 2010, 5:29pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/2 "2010-05-04T17:29:27Z")
Here you go - not a cooling blanket but… [http://www.secure-bedfan.com/The\_Bedfan\_p/bf-mbj.htm&click=17](http://www.secure-bedfan.com/The_Bedfan_p/bf-mbj.htm&click=17) ---
**Author:** ![DiosaBellissima](https://avatars.discourse-cdn.com/v4/letter/d/a8b319/32.png) [@DiosaBellissima](https://boards.straightdope.com/u/DiosaBellissima)\ **Post date:** [May 4, 2010, 5:31pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/3 "2010-05-04T17:31:18Z")
**Dangerosa** , that’s pretty nifty, but I imagine it isn’t too different from throwing the three fans around my bed like I do in summer. It’s an interesting idea, though! Know of anyone who has used one? ---
**Author:** ![Ogre](https://avatars.discourse-cdn.com/v4/letter/o/ecb155/32.png) [@Ogre](https://boards.straightdope.com/u/Ogre)\ **Post date:** [May 4, 2010, 5:39pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/4 "2010-05-04T17:39:47Z")
Well, you’d need to be able to run coolant through your blanket, which would require a heat exchanger somewhere, which means that the heat your blanket is sapping from your body would have to be lost somewhere. That would require a lot more hardware, plus the coolant itself, and would be expensive. Also, you’d end up heating your house more because you’d be adding the heat output of another electric motor to your house (unless you exhausted it to the outside somehow. Also, you would probably be in considerable danger of hypothermia and death. Your body temperature is lower when you sleep anyway, and constantly bleeding off body heat during the night is probably not a very healthy idea. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [May 4, 2010, 5:40pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/5 "2010-05-04T17:40:39Z")
> [@DiosaBellissima](#): > > But last night, while thinking of all of these things, I came to wonder why there isn’t a cooling equivalent of the heating blanket? It’d be a great idea- I could run my AC a little warmer, but keep my bed nice and cool. Save energy, be more comfortable, everybody is happy. The only thing I can think of is that cooling is harder than heating, so it just isn’t economical to produce such a thing. Is this on the right track? I also thought that maybe there wouldn’t be a market for such an item, hence the poll above. It’s easy to heat something: just run electrical current through resistors, or burn fuel. It’s more difficult to cool something because the energy you take from that thing (along with the energy used to drive the cooling cycle) has to be dumped somewhere else. Your car has a condenser coil out in front of the engine, dumping the heat that was collected from the car’s cabin. Your room AC has a condenser coil dangling outside the window, dumping heat to the great outdoors. Your refrigerator has a condenser coil on its rear surface, dumping heat from the fridge’s interior into your kitchen. If you want a cooling blanket, not only do you need the blanket itself with its cooling element, you need a place to dump all the heat it collects from your body. That makes it a much more complicated (and costly) proposition than a simple heating blanket. If you want to avoid having a separate heat-dumping element on the floor next to the bed, it could be integrated into the top surface. The blanket would have a cold side and a hot side with a layer of insulation between the two, and a pump somewhere circulating coolant between the two layers. Again, much more costly, complicated, and cumbersome than a simple electric heating blanket. Thermoelectric cooling is another technology that could work. Glossing over the details: when you apply a voltage to move electrical current around a circuit composed of two dissimilar wires, one junction gets hot, the other gets cold. Build a blanket composed of many such circuits - with the “cold” junctions on one side of the blanket, and the “hot” junctions on the other side - and you’ve got your cooling blanket. CPU coolers are available that operate on this principle, as are a number of other devices. Not terribly cheap or efficient, but much more reliable than the more common gas/liquid/compressor refrigerant cycles. Bottom line? A cooling blanket is likely to be much more expensive, heavy, complicated than a plain old electric heating blanket. ---
**Author:** ![Ogre](https://avatars.discourse-cdn.com/v4/letter/o/ecb155/32.png) [@Ogre](https://boards.straightdope.com/u/Ogre)\ **Post date:** [May 4, 2010, 5:42pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/6 "2010-05-04T17:42:04Z")
I suppose you could use cool water as your coolant, lacing your blanket with a light hose to circulate it. You could hook one end to the faucet and the other to a drain. Of course, then you’d be spending a mint on water every month, and you still have the problem of hypothermia. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [May 4, 2010, 5:44pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/7 "2010-05-04T17:44:36Z")
Back when I had a water-bed, by shutting off its heater it would cool. Big-time. I would wake up freezing during a heat wave. ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [May 4, 2010, 5:51pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/8 "2010-05-04T17:51:18Z")
Technical issues aside, I’m not sure a cold blanket is going to give you what I think you want. I’m the same way; ideally I want the room to be cold so I can be warm under the blanket. Having a cold blanket is not going to provide that. You’ll just end up shivering on a cold bed. It’s the **air** that I want cold, not the bed. What I have is a window AC unit in the bedroom blowing right at the bed, with the house central air off, and that works perfectly. Not wasting energy cooling the whole house, but being able to sleep comfortably in a nice icy cold room. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [May 4, 2010, 6:03pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/9 "2010-05-04T18:03:56Z")
I don’t know why folks are so concerned about hypothermia. We’re not talking about multi-ton cooling capacities here; just a smidge of cooling, probably also utilizing a thermostat to maintain a particular temperature. ---
**Author:** ![Ogre](https://avatars.discourse-cdn.com/v4/letter/o/ecb155/32.png) [@Ogre](https://boards.straightdope.com/u/Ogre)\ **Post date:** [May 4, 2010, 6:10pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/10 "2010-05-04T18:10:09Z")
You don’t need multi-ton cooling capacity for hypothermia. All you need is to drop the resting body temperature below 95 degrees fahrenheit to have health consequences. ---
**Author:** ![Alpha\_Twit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alpha_twit/32/265_2.png) [@Alpha\_Twit](https://boards.straightdope.com/u/Alpha_Twit)\ **Post date:** [May 4, 2010, 6:14pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/11 "2010-05-04T18:14:14Z")
I would have to wonder how such a blanket or bed specific cooling system would deal with high humidity environments. Waking up with a cold, **wet** blanket isn’t likely to be good for anyone. > [@kayaker](#): > > Back when I had a water-bed, by shutting off its heater it would cool. Big-time. I would wake up freezing during a heat wave. My experience is similar. Lying on a bladder of 80 degree F water is a remarkably efficient way of shedding heat. ---
**Author:** ![Omar\_Little](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/omar_little/32/269_2.png) [@Omar\_Little](https://boards.straightdope.com/u/Omar_Little)\ **Post date:** [May 4, 2010, 6:49pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/12 "2010-05-04T18:49:20Z")
> [@DCnDC](#): > > Technical issues aside, I’m not sure a cold blanket is going to give you what I think you want. > > I’m the same way; ideally I want the room to be cold so I can be warm under the blanket. Having a cold blanket is not going to provide that. You’ll just end up shivering on a cold bed. It’s the **air** that I want cold, not the bed. > > What I have is a window AC unit in the bedroom blowing right at the bed, with the house central air off, and that works perfectly. Not wasting energy cooling the whole house, but being able to sleep comfortably in a nice icy cold room. I like the air on my face outside the bed to be cool so that my body heat under the comforter is warm and cozy but not hot. A cooling blanket would not achieve that for me. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [May 4, 2010, 6:51pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/13 "2010-05-04T18:51:04Z")
> [@Ogre](#): > > You don’t need multi-ton cooling capacity for hypothermia. All you need is to drop the resting body temperature below 95 degrees fahrenheit to have health consequences. :rolleyes: Fine. Turn the dial from “smidge” to “half a smidge” of cooling. ---
**Author:** ![AmericanMaid](https://avatars.discourse-cdn.com/v4/letter/a/e480ec/32.png) [@AmericanMaid](https://boards.straightdope.com/u/AmericanMaid)\ **Post date:** [May 4, 2010, 6:53pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/14 "2010-05-04T18:53:37Z")
I have awful circulation so I’m cold most of the time. Even on hot days, I need something heavy on my mid-section to fall asleep. Fan on face and feet uncovered. I don’t think I could sleep in a cooling blanket. ---
**Author:** ![control-z](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@control-z](https://boards.straightdope.com/u/control-z)\ **Post date:** [May 4, 2010, 7:01pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/15 "2010-05-04T19:01:54Z")
I’d like a seat cooler for my car; my back gets hot on sunny/hot days. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [May 4, 2010, 7:05pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/16 "2010-05-04T19:05:44Z")
> [@control-z](#): > > I’d like a seat cooler for my car; my back gets hot on sunny/hot days. I rented a Lincoln LS five years ago that had this feature. Handy in the desert southwest of the US. ---
**Author:** ![The\_Tao\_s\_Revenge](https://avatars.discourse-cdn.com/v4/letter/t/73ab20/32.png) [@The\_Tao\_s\_Revenge](https://boards.straightdope.com/u/The_Tao_s_Revenge)\ **Post date:** [May 4, 2010, 8:05pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/17 "2010-05-04T20:05:03Z")
Why not combine them to make a blanket with climate control? If it senses part of the body is too warm it turns on the coolant, if too cold it turns on the heat. ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [May 4, 2010, 9:58pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/18 "2010-05-04T21:58:36Z")
> [@Ogre](#): > > You don’t need multi-ton cooling capacity for hypothermia. All you need is to drop the resting body temperature below 95 degrees fahrenheit to have health consequences. except for those of us who’s normal basal temp is 94 =) I am running a fever at 98. ---
**Author:** ![Dangerosa](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Dangerosa](https://boards.straightdope.com/u/Dangerosa)\ **Post date:** [May 4, 2010, 10:16pm UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/19 "2010-05-04T22:16:44Z")
> [@DiosaBellissima](#): > > **Dangerosa** , that’s pretty nifty, but I imagine it isn’t too different from throwing the three fans around my bed like I do in summer. It’s an interesting idea, though! Know of anyone who has used one? Nope, just one of those weird internet things. I suspect its a little better than a fan since it would run between the sheets - I also suspect I wouldn’t like it. ---
**Author:** ![MeanOldLady](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/meanoldlady/32/10737_2.png) [@MeanOldLady](https://boards.straightdope.com/u/MeanOldLady)\ **Post date:** [May 5, 2010, 12:04am UTC](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302/20 "2010-05-05T00:04:08Z")
Well sometimes I want the bed cold. Not the room cold so that I can enjoy a warm bed. Sometimes it’s muggy as fat man balls, and I’m hot, and want to cool the hell down without running the a/c all day. I need a cooling blanket. \ Make this happen. Post haste! [Next page](https://boards.straightdope.com/t/heating-blankets-popular-cooling-blankets-non-existent-commercially-would-you-buy-one/538302.md?page=2)