Theory 31/Lewis Number/Thermoregulation
Sweating Is a Lewis Problem
The claim
The effectiveness of sweating is set by the Lewis number of the air at the skin, so humid and dry air of equal temperature cool very differently.
01Mechanism
Heat and water vapour diffuse at different rates; the ratio determines how much cooling is achieved per unit of water evaporated.
02Prediction
Cooling per unit sweat should track Lewis.
03Refutation
Cooling tracking temperature alone would remove humidity.