Body & HealthHow it works

How sweat cools you even though it's body temperature.

You have 2 to 4 million sweat glands. It is not the sweat that cools you but its evaporation: every gram of water that turns to vapour on your skin pulls about 2.4 kilojoules of heat out of it. In humid air almost nothing evaporates and sweat drips off uselessly. That is why 32 degrees in humid air feels worse than 38 in dry air.

Useful: Wind and dry air cool you because they speed up evaporation, not because they are colder.

Source: en.wikipedia.org

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