What process allows perspiration to cool the body?

Aug 1, 2016

Water specific heat is 4.178 J/g-'K. Its mass can be taken as 1.0g/$c {m}^{3}$ for this example. The heat of vaporization for water is 2257 J/g.
So, every gram (about 1 mL or $c {m}^{3}$) of water evaporated from your body removes 2257 Joules of heat from your body (neglecting possible losses also from raising the sweat temperature before it evaporates - the specific heat value).