1
$\begingroup$

When my face is full of sweat, I go near the A.C. and when the cool air touches my sweat it feels colder than dry parts? Why does the sweat feel colder than dry parts?

$\endgroup$
2
  • 11
    $\begingroup$ Because it evaporates and removes heat from your body. $\endgroup$ Sep 8, 2017 at 15:04
  • $\begingroup$ Sweat is supposed to cool you down and has been evolutionarily ‘designed’ and kept that way. $\endgroup$
    – Jan
    Sep 9, 2017 at 7:28

1 Answer 1

6
$\begingroup$

The heat of evaporation of the water is $\pu{2260J/g}$. That means for every one gram of water, it takes $\pu{2260J}$ of energy to vaporize it. The water (evaporating) takes the needed heat energy from your $\pu{37 ^\circ C}$ body.

Source

$\endgroup$
4
  • 2
    $\begingroup$ And OP would feel the same effect if they used plain tap water instead of sweat. $\endgroup$
    – Jan
    Sep 9, 2017 at 7:28
  • $\begingroup$ @Jan Sorry but what does OP mean? $\endgroup$ Sep 9, 2017 at 8:47
  • $\begingroup$ But then I should feel the same when near a fan, but A.C. seems to be much cooler. Why? $\endgroup$ Sep 9, 2017 at 8:49
  • 1
    $\begingroup$ @RamKeswani OP is original poster; in this case the person who asked the question (you). And you do feel the same effect near a fan. The aircon is colder because it is blowing cool air at you rather than ambient air. $\endgroup$
    – Jan
    Sep 9, 2017 at 9:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.