Defogger Controls problems of the 2003 Chevrolet S10

105 to110 degree temperature air blowing onto feet with all heater controls shut off and in the coolest temperature setting. Dealer said this is normal, and provided a service bulletin from gm stating that on these trucks this situation is because of the pressure created by the wind blowing over the windshield, forcing the air into the passenger compartment. Very uncomfortable to drive.