Do blankets warm you?

Believers of the Greenhouse Effect all use the same analogy to get you to believe in their junk science. The site Skeptical Science sets the standard in this article:

So have climate scientists made an elementary mistake? Of course not! The skeptic is ignoring the fact that the Earth is being warmed by the sun, which makes all the difference.

To see why, consider that blanket that keeps you warm. If your skin feels cold, wrapping yourself in a blanket can make you warmer. Why? Because your body is generating heat, and that heat is escaping from your body into the environment. When you wrap yourself in a blanket, the loss of heat is reduced, some is retained at the surface of your body, and you warm up. You get warmer because the heat that your body is generating cannot escape as fast as before.

Link

And more:

To summarise: Heat from the sun warms the Earth, as heat from your body keeps you warm. The Earth loses heat to space, and your body loses heat to the environment. Greenhouse gases slow down the rate of heat-loss from the surface of the Earth, like a blanket that slows down the rate at which your body loses heat. The result is the same in both cases, the surface of the Earth, or of your body, gets warmer.

Link

NASA reminds us that:

The greenhouse effect is the way in which heat is trapped close to the surface of the Earth by “greenhouse gases.” These heat-trapping gases can be thought of as a blanket wrapped around the Earth, which keeps it toastier than it would be without them.

Link

You got that? Blankets warm you! Their logic is so sound that they couldn’t possibly be wrong, could they?

What empirical evidence do they provide for such an assertion? None!

Do they even attempt to predict what temperature a blanket could force? No!

Any such attempt would be very embarrassing for them, so instead they just leave it to the reader’s imagination.

First a note: there is no doubt that a blanket can make you warmer by blocking convection. The issue at hand is whether there is a warming due to radiative heat transfer, as is claimed for the greenhouse effect by analogy.

Let’s consider the case of a typical cotton blanket, whose emissivity ranges from 0.81 to 0.88 [Bellivieu 2019], depending on humidity. I will choose 0.85 for an average humidity condition; The exactness hardly matters. According to the verified program provided in my article The Dumbest Math Theory Ever, a blanket with an emissivity of 0.85 placed on a human being whose normal temperature is at 37°C, should produce a final skin temperature of …

$ ALB=0 TSI=2090.8 bash gheffect 0.85

Sec | Upwelling |   Temp    | GH Effect |  Trapped  | To Space
  1 | 522.700 W |  36.701 C | 444.295 W | 222.148 W | 300.553 W
  2 | 744.848 W |  65.389 C | 410.973 W |  94.413 W | 428.287 W
  3 | 839.260 W |  75.642 C | 396.811 W |  40.125 W | 482.575 W
  4 | 879.386 W |  79.738 C | 390.792 W |  17.053 W | 505.647 W
  5 | 896.439 W |  81.436 C | 388.234 W |   7.248 W | 515.452 W
  6 | 903.687 W |  82.151 C | 387.147 W |   3.080 W | 519.620 W
  7 | 906.767 W |  82.453 C | 386.685 W |   1.309 W | 521.391 W
  8 | 908.076 W |  82.582 C | 386.489 W |   0.556 W | 522.144 W
  9 | 908.632 W |  82.636 C | 386.405 W |   0.236 W | 522.464 W
 10 | 908.869 W |  82.659 C | 386.370 W |   0.100 W | 522.600 W
 11 | 908.969 W |  82.669 C | 386.355 W |   0.043 W | 522.657 W
 12 | 909.012 W |  82.673 C | 386.348 W |   0.018 W | 522.682 W
 13 | 909.030 W |  82.675 C | 386.345 W |   0.008 W | 522.692 W
 14 | 909.038 W |  82.676 C | 386.344 W |   0.003 W | 522.697 W
 15 | 909.041 W |  82.676 C | 386.344 W |   0.001 W | 522.699 W
 16 | 909.042 W |  82.676 C | 386.344 W |   0.001 W | 522.699 W
 17 | 909.043 W |  82.676 C | 386.344 W |   0.000 W | 522.700 W

82.6°C ! Really hot!

Note that I set the albedo to zero. This is because I figure any scattering of photons between human and blanket will find its path back to the human (and thus “should” cause warming), with very little leakage at the edges of the blanket. But let us be as generous as possible to climate alarmists and say the blanket has an albedo of 0.22 (The highest value found for cotton in scientific literature: Source 1, Source 2). What then?

$ ALB=0.22 TSI=2090.8 bash gheffect 0.85

Sec | Upwelling |   Temp    | GH Effect |  Trapped  | To Space
  1 | 407.706 W |  18.040 C | 346.550 W | 173.275 W | 234.431 W
  2 | 580.981 W |  44.999 C | 320.559 W |  73.642 W | 334.064 W
  3 | 654.623 W |  54.635 C | 309.513 W |  31.298 W | 376.408 W
  4 | 685.921 W |  58.484 C | 304.818 W |  13.302 W | 394.404 W
  5 | 699.222 W |  60.081 C | 302.823 W |   5.653 W | 402.053 W
  6 | 704.875 W |  60.752 C | 301.975 W |   2.403 W | 405.303 W
  7 | 707.278 W |  61.036 C | 301.614 W |   1.021 W | 406.685 W
  8 | 708.299 W |  61.157 C | 301.461 W |   0.434 W | 407.272 W
  9 | 708.733 W |  61.208 C | 301.396 W |   0.184 W | 407.522 W
 10 | 708.918 W |  61.230 C | 301.368 W |   0.078 W | 407.628 W
 11 | 708.996 W |  61.239 C | 301.357 W |   0.033 W | 407.673 W
 12 | 709.029 W |  61.243 C | 301.352 W |   0.014 W | 407.692 W
 13 | 709.043 W |  61.245 C | 301.349 W |   0.006 W | 407.700 W
 14 | 709.049 W |  61.245 C | 301.349 W |   0.003 W | 407.703 W
 15 | 709.052 W |  61.246 C | 301.348 W |   0.001 W | 407.705 W
 16 | 709.053 W |  61.246 C | 301.348 W |   0.000 W | 407.706 W
 17 | 709.054 W |  61.246 C | 301.348 W |   0.000 W | 407.706 W

61.2°C ! Still very hot.

OK, I’m now going to be extremely generous, and use an emissivity value of 0.5, which is not even scientifically justifiable, but let’s give the alarmists a huge advantage. What then?

$ ALB=0.22 TSI=2090.8 bash gheffect 0.5

Sec | Upwelling |   Temp    | GH Effect |  Trapped  | To Space
  1 | 407.706 W |  18.040 C | 203.853 W | 101.927 W | 305.780 W
  2 | 509.633 W |  34.746 C | 152.890 W |  25.482 W | 382.224 W
  3 | 535.114 W |  38.525 C | 140.149 W |   6.370 W | 401.336 W
  4 | 541.485 W |  39.448 C | 136.964 W |   1.593 W | 406.113 W
  5 | 543.077 W |  39.678 C | 136.167 W |   0.398 W | 407.308 W
  6 | 543.475 W |  39.735 C | 135.968 W |   0.100 W | 407.606 W
  7 | 543.575 W |  39.750 C | 135.919 W |   0.025 W | 407.681 W
  8 | 543.600 W |  39.753 C | 135.906 W |   0.006 W | 407.700 W
  9 | 543.606 W |  39.754 C | 135.903 W |   0.002 W | 407.704 W
 10 | 543.607 W |  39.754 C | 135.902 W |   0.000 W | 407.706 W
 11 | 543.608 W |  39.754 C | 135.902 W |   0.000 W | 407.706 W

Now we get only 39.8°C, for a total warm up of 2.8°C – by a blanket that can only be heated by the human, and starts off colder (or same) as the human.

So is there any evidence to support the heating of human skin by a passively heated blanket via backradiation ?

However, if a cotton blanket heated to 90°C is in contact with skin the patient does not experience the same tissue injuries, because the blanket has less than one third the specific heat of skin. In addition, the blanket has less than 1/1000 the density of skin (the density of a blanket is about 1 kg/m³ because it is roughly half cotton and half air.) The blanket can give up all of its heat to the skin yet raise the temperature no more than 1/80th of the 70°C temperature difference, or about 1°C.

[ House 2011 ]

This scientist rightfully does not acknowledge warming by radiative effect. The blanket must be theoretically warmed to 90°C to achieve a rise of about 1°C. A table of empirical results is also provided in [House 2011]:

Body PartUnheated BlanketsBlankets Warmed to 43.3°CBlankets Warmed to 65.6°C
Abdomen0.17°C1.11°C2.39°C
Lower Legs0.33°C0.89°C1.11°C
[ House 2011], Table 2, Converted to Celcius

Though there is obviously a tiny amount of warming due to blocking convection, we don’t see any warming as predicted by GH effect radiative heat transfer theory. We should’ve seen a very generous 2.8°C warming as predicted by such a theory in the column Unheated Blankets. We don’t even see such a high number with blankets externally heated to 65.6°C !

Now we move onto [Kabbara 2002]. In this paper we see how expensive equipment can be used to maintain a patient’s temperature. Figure 6 shows how externally heated air prevents a patient’s temperature from falling. But one may ask: What is the purpose of this expensive equipment when climate “scientists” already know that a non-externally heated blanket should raise skin temperature by at least the very generous 2.8°C?

Would you trust these climate “scientists” with your health? Do you think they really believe what they claim?

And now we move onto: US Patent – US6078026A

The blanket A has a maximum power draw of 6.5 amps. With fully charged batteries, the blanket will reach its target temperature (i.e. 100 degrees Fahrenheit or 38 degrees Celsius) approximately 5 minutes and will remain heated for five to eight hours.

Patent US6078026A

An external power source to raise T to 38°C?

Why need external power or even a patent when a simple blanket ought to do the trick?

Please do not object to this article because I based this off a normal temperature of 37°C. Even a hypothermic temperature of 33°C should be raised by 2.72°C, IF the GH effect blanket analogy held any merit.

A search on google scholar for “hospital blankets temperature” should convince anyone with integrity that blankets don’t raise your skin temperature in accordance to radiative transfer theory. For if they did, most of the discussion and science in that search would be moot: human-only heated blankets would solve the problems and special technology would not be necessary.

Skeptical Science finishes off their article:

So global warming does not violate the second law of thermodynamics. And if someone tells you otherwise, just remember that you’re a warm human being, and certainly nobody’s dummy.

Link

I’ll translate that for you: If you believe their sophistry, you are a dummy!

While using poetic license it is alright to say that blankets warm you, but using actual science, it is not correct. The best a blanket can do is keep you warm, but never make you warmer.

Enjoy 🙂 -Zoe

Addendum

Blanket(s) can suppress your perspiration and make you sick from your own urea, thus causing your temperature to go up. However, this could never be a proper analogy for the greenhouse effect.

15 thoughts on “Do blankets warm you?

  1. A quick note regarding your “First a note: there is no doubt that a blanket can make you warmer by blocking convection.” – did you really mean to say can make you warmer, or keep you warmer?

    Liked by 1 person

    1. Convection can prevent your skin from reaching the normal 37C. A thermometer can’t be wrapped in your skin all around. I allow for a tiny bit of warming. You can disregard my comment if you know what I mean. I anticipate that some papers will show some tiny warming, and I want to have a ready explanation.

      Like

      1. Yes, well, normal is relative and average is conveniently inaccurate. Insulation dampens convection but dampness tends to heighten it. Sleep outdoors for two nights @ -5C, one night with your face inside the sleeping bag breathing warm air and one night with it outside breathing cold air. On which night is your skin likely to be warmer?

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  2. “The issue at hand is whether there is a warming due to radiative heat transfer, as is claimed for the greenhouse effect by analogy.”

    Nope. It is simply about the fact that clothes reduce cooling, therefore the body is warmer than it would be otherwise. It is not meant to be a 1-1 analogy. If you think otherwise, prove it.

    Liked by 1 person

    1. Science doesn’t work by analogy. GHGs (with emissivity ~= 0.792) are said to raise surface temperature by ~33C due to radiative transfer theory. Yet cotton blankets (with emissivity = 0.85) are shown AT BEST to raise temperature less than 1C due to a completely different principle.

      If you don’t see a problem with this, it’s probably because you went beyond the domain of science.

      Like

      1. Why human temps are not dramatically pushed around by our surroundings is indeed an interesting question, one I hope I will be able to answer over the years/months/weeks.

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        1. There is already is an explanation. It’s the 2nd law of thermodynamics. 2nd law was derived by countless experiments. Doubtful you will find an exception and remove this law.

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  3. Skeptical Science is a heap of horrible stinky garbage written by someone with a huge chip on their shoulder, and was obviously given its title in order to attract readership among people hoping to find skeptical sources – a ploy at about the 11-year old cleverness level. Viscerally disgusting on every level and really should be beneath our attention, but worth fighting because of that ploy. Thanks for the great article!

    Liked by 1 person

    1. Skeptical Science was founded by the cartoonist John Cook – he of the notorious 97% consensus study. Cook is known for dressing up in Nazi garb. The fact that Skeptical Science is also known as SS is quite ironic and revealing of the fascist leanings of the Klimat Kult Krowd (KKK).

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  4. If the sleeping bag is made of good insulating material, it will allow you to keep your body warm for some time when you are outdoors. The lower the outside temperature, the faster you lose heat.

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    1. Absolutely true. Insulation will help KEEP your temperature, but not raise it.

      Spending less money will lead to more savings. But the correct analogy of temperature in this context is: income. Your income will not change the more you save. You need a raise for that.

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  5. Zoe:

    Does the blanket analogy (really, a metaphor, since, as you’ve pointed out, it does not work by trapping radiatively active gases), work better with your concept of geothermal? In other words, the body acts as the earth’s core – putting out heat – which presumably would warm the blanket (treated here as the “surface”)?

    Indeed, isn’t the reference to these gases as “green house” gases also misleading? Does not a green house primarily work by preventing convection?

    Liked by 1 person

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