Biology Question: Heat Above Body Temperature (average, temperatures, humidity, normal)

[CairoCanadian]

Simple enough question, but here it is: if the difference between humid heat and dry heat is the body's ability to cool off through evaporation, does this effect disappear when the ambient temperature is above 37.5C or so? ( I know body temperature varies, but just an average number. )

And does that mean weather forecasts that give a ''feels like'' temperature above 37.5C are lying? ( I've seen ''Feels like 42C'' on some forecasts. )

[Patricius Maximus]

I have no expertise on biology, but I don't think there would be any difference. I've noticed no difference myself, but then again, humid or dry I am always on the knife-edge of heat stroke at such temperatures, so any difference wouldn't be noticed.

However, I would think the mechanism of the sweat evaporating wouldn't be affected due to the outside temperature being above body temperature because the sweat would heat up (in full sun, let's say) and evaporate anyway. Of course cooling off is more difficult at such temperatures, but that's just the normal curve of increasing temperature discomfort.

[nei]

No because evaporation can cool you below the outdoor temperature. The lowest temperature evaporation can you cool to is called the wet bulb temperature. If it's more humid, your body can't cool itself and humidity becomes much more dangerous at temperatures above body temperature.

[CairoCanadian]

Originally Posted by nei

No because evaporation can cool you below the outdoor temperature. The lowest temperature evaporation can you cool to is called the wet bulb temperature. If it's more humid, your body can't cool itself and humidity becomes much more dangerous at temperatures above body temperature.

Fascinating! I didn't know this.

It would answer why when we had 38C and a humidity percentage of 8% it felt surprisingly tolerable.