Brain teaser

[Drilon]

One day I was thinking and I suddenly asked myself this question.

 

 

If our brain temperature is 37 degrees Celsius, why do we feel uncomfortable (hot) when it's the same outside.

[John Cuthber]

Because we have to shed the waste heat that metabolism generates. We can do that by sweating (the heat is used to evaporate the water) but it's easier to do it if we can lose heat simply by conduction to the outside air.

Normally the skin is a fair bit cooler than 37C so the excess heat is conducted (as well as carried by the blood) to the skin. When the air temperature is as warm as 37C we have more difficulty losing the waste heat we generate.