My understanding too is that Windchill Equivalent Temperature is merely an index of human comfort. Have a look at this publication.
Windchill
Note especially the reference to inanimate objects in the first paragraph. However if an object is wet the increased evaporation brought about by airflow could cause the temperature do drop below ambient. The same effect causes a wet bulb thermometer to record a temperature below ambient depending on relative humidity. Click here to see what the FAA have to say about wind effect. Scroll down to Appendix 3 paragraph 7(j).
FAA AC20-117
I think there is a misprint here in that ‘practical’ should read ‘impractical’
Regards
Xacto