1999 Chevrolet Express Van Owner's Manual - Page 81

yellowblue Rear Doors CAUTION: It can be dangerous to drive with the rear doors open because carbon monoxide (CO) gas can come into your vehicle. You can't see or smell CO. It can cause unconsciousness and even death. If you must drive with the rear doors open or if electrical wiring or other cable connections must pass through the seal between the body and the rear doors: D Make sure all other windows are shut. D Turn the fan on your heating or cooling system to its highest speed with the setting on VENT, HEAT, BLEND or DEF. Additionally, on vehicles with heating/air conditioning systems, NORM A/C or BI-LEVEL A/C can be used. That will force outside air into your vehicle. See "Comfort Controls" in the Index. D If you have air outlets on or under the instrument panel, open them all the way. See "Engine Exhaust" in the Index. To open the rear doors from the outside, open the passenger side rear door first. Pull the handle toward you to open the door. 2-13