Temperature of atmosphere at a high altitude is around 500 degree celsius.Yet an animal there would freeze to death and not boil.Explain

Air temperature generally decreases with altitude. That's why you see more snow on the mountains than the valleys. So it's very unlikely to get so much hotter than the surface of the earth. An unprotected animal around 10,000 to 15,000 feet elevation is likely to freeze to death. Above 20,000 or 30,000 feet it is more likely to suffocate due to lack of oxygen.

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regards

Ramesh