Ben V-L and Maynard Handley correctlly argue that we do not really feel temperature:
Grasping Reality with Both Hands: Brad DeLong's Semi-Daily Journal: Yet More Unseasonable California Weather Blogging: You have a false premise: that we feel temperatures. What we feel is the heat flowing in or out of our bodies. As one textbook puts it: in a cold campground outhouse, would you rather sit on the metal toilet or the wooden one?
We are most comfortable in our active, awake state when the surroundings are some 20 degrees (F) below our temperature (so, 70's). Then our heat loss roughly equals our generated heat. Temperatures in the 50's have twice the heat loss and feel cool. The 20's aren't just 5% cooler in this perspective. They are more than three times as cool as 70's.
Another example where thinking on absolute scales is pretty useless is air pressure. If the pressures on either side of a door differ by a few percentages, it can rip your arm off.
Posted by: Ben V-L | January 15, 2007 at 05:23 PM
Grasping Reality with Both Hands: Brad DeLong's Semi-Daily Journal: Yet More Unseasonable California Weather Blogging: Adding to Ben V_L's point (which is certainly essentially correct as regards the perception of cold) a second aspect of the situation to remember is that what surely matters is not the speed of air molecules, but the speed at which chemical reactions occur.
The (very very rough) rule of thumb is that chemical reactions run twice as fast for each 10K rise in temperatures. This is sufficiently rough as to be useless as an actual quantitative guide, but gives you a feel for the rapidity with which reactions become faster as temperatures heat up.
Since we are warm-blooded, this is of mainly academic interest, but there's a whole lot of invertebrate life out there that doesn't have the benefit of our warm blood and for which this changing of the speed of chemical reactions presumably has real perceptual consequences (to the extent that insect brains, for example, have perceptions).
Posted by: Maynard Handley | January 16, 2007 at 01:09 PM