I think sometimes mine activate the heating element when the A/C function is turned on, it's worse on the passinger side. Dealer has looked at it but they don't know what to do.

Does seem to do a better job when the vehicle A/C is on the floor vents. Seems to pick up some of the cool air.

When they do work, it never last more than 15 -20 minutes, then they actually feel like they are getting hot.