I'd think here in Minnesota most people would would understand wind chill (and now the summer 'heat index') but it's amazing even some newscasters are totally clueless.
Wind chill measures the RATE of heat loss, not the actual final temperature. i.e. standing outside in still air, the body or car or house would lose a certain number of BTU in a certain time. Pick some (all fictitious) numbers: 100 btu in 60 seconds at 30 degrees F. The same temperature, with 30 mph wind, the object may lose 150 btu in the same 60 seconds. Wind chill is the temperature that it would lose the same 100 btu in 60 seconds. Maybe at say 10F and still air it would lose 100 btu/60 seconds. Voila, 30F, 30 wind, is called 10F wind chill.
However, the FINAL temperature is still 30F. The object simply cools down much faster, then tapers out to 30F. Unless there is evaporative cooling or something else, final is 30F, whether acheived in minutes or hours. A car does NOT start harder at deep windchills, it just gets cooled down faster. However, it sure seems that way, when I am out there trying to get things going.
Wind chill is very helpful to know how to dress, what to do with livestock, and generally how nasty it will be for living critters have to live or work outside.
speaking of which, right now sunday morning is 30F and light mist here. By tonight, expecting -5, snow, freezing rain, wind, and -30F windchills. Love to be outside, but very thainkful for an office job right now.
k