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-   -   Pretty interesting question that belongs here IMHO (http://physicshelpforum.com/thermodynamics-fluid-mechanics/176-pretty-interesting-question-belongs-here-imho.html)

alpha Jun 22nd 2008 11:47 AM

Pretty interesting question that belongs here IMHO
 
Why does wet skin get cold faster than dry? (Like when you leave bathroom and feel cold if there's any water on you).

topsquark Jun 22nd 2008 06:09 PM

Quote:

Originally Posted by alpha (Post 583)
Why does wet skin get cold faster than dry? (Like when you leave bathroom and feel cold if there's any water on you).

One word: evaporation. Evaporation is a process that soaks up (no pun intended) energy from its surroundings. So as the water on your body evaporates you will feel cooler.

As a more extreme example of this, walk not only out of the bathroom, but in front of a large fan. The moment you walk into the breeze it gets fairly cool, but as you stand there (ie. let the water evaporate) you warm up some.

-Dan

Mr Fantastic Jul 2nd 2008 04:14 AM

Quote:

Originally Posted by topsquark (Post 584)
One word: evaporation. Evaporation is a process that soaks up (no pun intended) energy from its surroundings. So as the water on your body evaporates you will feel cooler.

As a more extreme example of this, walk not only out of the bathroom, but in front of a large fan. The moment you walk into the breeze it gets fairly cool, but as you stand there (ie. let the water evaporate) you warm up some.

-Dan

Which of course is why humans sweat when they're hot .... to take advantage of this effect. Dogs can't sweat, so they pant.

And if you've ever done a lot of exercise and then stopped, you become drenched in sweat because you've stopped moving which means that the evaporative effect due to the movement is greatly diminished.

Mr Fantastic Jul 2nd 2008 04:22 AM

Quote:

Originally Posted by alpha (Post 583)
Why does wet skin get cold faster than dry? (Like when you leave bathroom and feel cold if there's any water on you).

Now you know the answer to this question, you might want to consider the question of why your feet feel colder standing on bathroom tiles than on the bathroom mat.

Note: The temperature of both tiles and mat is the same (room temperature) (do the experiment to confirm this) .......


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