Why wet skin feels cold

Dear Tom,
Why does wet skin feel so cold?
Robert Allen
Dear Robert,
It's due to the behavior of water molecules: They're in constant motion and
the warmer they are, the faster they're moving. We sense that motion as
heat.
In liquid form, water molecules are vibrating and tumbling around because
they're not bonded together the way they are in ice. In order for a
within-liquid water molecule to escape from the liquid into the air -- to
evaporate -- it must obtain greater speed, and this can happen through
random collisions with other molecules in the liquid (which thereby lose
some of their speed).
If, after a collision, a particular molecule already at the water's surface
has sufficient speed to break into the air, it takes its energy (its heat)
with it. That's heat lost from the liquid, which therefore cools, and that's
why water evaporating from our skin gets cooler.