Re: How cold water feels

David,

You ask an interesting question. Unfortunately, to my knowledge, there 
isn't a very specific answer. Fortunately, you can find out for yourself!

One possibility is that we associate wetness with "clamminess" and perceive 
the water as colder than air. Another possibility is that, being constantly 
surrounded by air, we adapted to its temperature. Because we typically are 
adapted to air but not water, the change to "wet/clammy" may involve a 
change in perceived temperature. 

Here are a couple of simple preliminary tests that might help you answer 
your own question!

1) Try experimenting with a variety of water temperatures. Try water that 
is warmer than the air and colder than the air (use your refrigerator or 
microwave and a thermometer, but be careful not to make the temperatures 
too extreme). Get a few of your friends to participate by placing their 
hand in a basin of the heated or cooled water and record their responses. 
You might make up a little "survey" sheet where they can rank their 
perception of the water on a scale of 1-7. For example
        1= Water feels much colder than the air
        2
        3
        4=Water feels like the same temperature as the air
        5
        6
        7=Water feels much warmer than the air

Does their perception of the water temperature vary according to actual 
temperature? Does the perception typically fall below the actual temp (Is 
it perceived as colder?)?

2) Maybe this change in perception has something to do with the fact that 
we are almost always surrounded by air. Perhaps we "adapt" to the air 
temperature. You can test this too. Try having a couple of your friends hit 
the swimming pool for an afternoon. Repeat a test similar to the one above 
while your friends are floating around in the water. Is there a difference 
in your results from Experiment 1?

Another factor you may wish to consider is evaporation. Our bodies 
constantly tweak our internal temperature to keep it stable. For example, 
when our body temperature increases with exercise, we begin to sweat. The 
evaporation of sweat on our skin is an important way in which to lower body 
temperature. If the temperature judgements in your experiments are made 
after the subject has removed his hand from the water (and into air), 
evaporation might occur. This might cause the water to be perceived as 
cooler than the air.

I'd love to hear what you discover. If you like, you can email me at 
llholt@facstaff.wisc.edu Have fun!

Lori Holt