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

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SUMMARY

When lying on the ground at night without cover, significant body heat loss occurs primarily due to radiation. In dry climates, the sky temperature can plummet to -40°C, while the skin temperature remains around 30°C. The discussion emphasizes the importance of accurately estimating the effective surface area for radiation calculations, suggesting that using a surface area of 0.9 m² (half of the typical 1.8 m²) is more appropriate for exposed skin. This adjustment is crucial for calculating the net rate of energy loss accurately.

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  • Understanding of thermal radiation principles
  • Knowledge of skin temperature and environmental temperature effects
  • Familiarity with basic physics equations related to energy loss
  • Ability to calculate surface area in relation to body exposure
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This discussion is beneficial for physicists, outdoor enthusiasts, survivalists, and anyone interested in understanding body heat loss in cold environments.

disneychannel
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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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