1996 GMC Savana Van Owner's Manual - Page 86

It canbe dangerous to drive with the rear swing-out windows or rear door@) 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 swing-out windows or rear door@) open ifor electrical wiring or other cable connections must pass through the seal between the body and the rear swing-out windowsor reardoor(s): Make sure all windows are shut. CAUTION: (Continued) Turn the fan on your heating or cooling system to its highest speed the setting with on VENT, HEAT, BLEND or DEF. Additionally, on vehicles with heatingair conditioning systems, NORM A/C or BI-LEV A/C can be used. That will force outside air into your vehicle. See "Comfort Controls'' in the Index. If you have air outlets on under the or instrument panel, open them all the way. See "Engine Exhaust" in the Index. Horn Press one of the horn buttons at each side of the steering wheel to sound the horn. 2-28