The present invention includes methods, systems and computer-readable media for more accurately determining wind chill temperature, T.sub.wc, equivalent temperature, T.sub.eq, time to freeze, t.sub.f, facial temperature, T.sub.f.sup.m+.DELTA.t, as a function of time and the altitude correction factor, .DELTA.t.sub.f/1000. The wind chill model of the present invention accounts for the two major heat losses (forced convection, radiation) and a minor heat loss (evaporative cooling) from the facial surface and is also capable of accounting for the two major heat gains (metabolic, solar) at the facial surface due to the individual's physical activity and the presence of sunshine. The wind chill model of the present invention also provides a more accurate value for the wind velocity at head level.