Advances, shortcomings, and recommendations for wind chill estimation.

This article discusses briefly the advances made and the remaining short-comings in the "new" wind chill charts adopted in the US and Canada in 2001. A number of indicated refinements are proposed, including the use of whole body models in the computations, verification of heat exchange coefficients by human experiments, reconsideration of "calm" wind conditions, reconsideration of frostbite threshold levels, the inclusion of cold-related pain and numbness in the charts, etc. A dynamic numerical model is applied to compare the effects of wind speeds, on the one hand, and air temperatures, on the other, on the steady-state exposed facial and bare finger temperatures. An apparent asymmetry is demonstrated, favoring the effects of wind speeds over those of air temperatures for an identical final facial temperature. This asymmetry is reversed, however, when SI unit changes in these quantities are considered.