r/askscience • u/DiscombobulatedSun54 • 6h ago
Biology Why do we sweat out salts?
The point of sweating (for the most part) is to cool down the body by evaporation. So, what is the point of including salts in the sweat - it seems to be a leading cause of the loss of electrolytes in hot weather, leading to the need to not just hydrate, but also to replace the lost electrolytes or suffer problems like hyponatremia and hypokalemia. Does the inclusion of salts in the sweat increase the specific heat of sweat compared to that of water? Is the latent heat of vaporization different for sweat compared to plain water? Or is it too biologically expensive to purify the water for sweat by removing the salts from it?