trouble is aircons are part of the problem:
they use heat to move heat, so the heat bill for using one of these is the amount of heat moved, plus some for operational needs.
the thing is, humans being what they are, the hotter it gets, the more the aircon gets used. could easily end up being a vicious circle.
that being said, I did actually have to have the AC on in the motor on the way back to work. I played footy in a stuffy oxygen free indoor pitch. but then me internal thermometer was reading 37 degrees C !!