From: utzoo!decvax!cca!hplabs!soreff@sri-unix
Newsgroups: net.misc
Title: Re: Wind-chill factor
Article-I.D.: hplabs.529
Posted: Fri Jul  9 09:28:37 1982
Received: Sun Jul 11 05:20:46 1982

I would think that cooling rate of a human (in reasonably cold weather) 
should depend only very weakly on the relative humidity. I'm assuming that
a thin layer of air neer the human reaches about body temperature or so,
and that the cooling rate depends on the rate of replacement of and
conduction through and evaporation into this mass of air. If the source of
this air is ambient air at some low temperature (eg below freezing) then
the initial partial pressure of water vapor will be very low (compared to
the saturation pressure of water at body temperature) even if the air is
fully saturated at ambient temperature. Cold air should always feel like dry
air to a warm blooded animal, basically because the vapor pressure of water
is strongly temperature dependent. Warning: This is only a guess, I don't
know the details of the physics of evaporative cooling.
Does anyone out there have a solid reference? -Jeffrey Soreff