If you haven't cut your A/C on in a while you might want to :)
Also, turn on the "outside" air on your car.. find the vents on your front windshield.. roll down all windows.. spray lysol (scented or unscented) for about 15 to 20 seconds each vent. This will help eliminate any bacteria in the venting system :)
Leave windows down for a bit. Run A/C, heat, and non A/C mode.