If you lie on the ground at night with no cover, you get cold rather

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Lying on the ground at night without cover leads to rapid cooling due to energy loss by radiation, especially in dry climates where sky temperatures can plummet to -40°C. The skin and clothing surface temperature can reach around 30°C, creating a significant temperature differential. The discussion centers on estimating the net rate of energy loss by radiation under these conditions. A participant suggests using a surface area of 1.8 m², but notes that only half of the body is exposed to the night sky, recommending to use half of that area for calculations. Accurate estimations are crucial for understanding thermal dynamics in such scenarios.
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If you lie on the ground at night with no cover, you get cold rather quickly. Much of this is due to energy loss by radiation. At night in a dry climate, the temperature of the sky can drop to -40oC. If you are lying on the ground with thin clothing that provides little insulation, the surface temperature of your skin and clothes will be about 30 oC.


Estimate the net rate at which your body loses energy by radiation to the night sky under these conditions.


I know how to do the problem, but my issue is what area should I use? I have been using 1.8 m 2 but it's not working out.

Thank You!
 
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I think, that's typical surface area of skin all around the body. Only half is exposed to night sky, though. So try half of that.
 

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