1998 GMC Envoy Owner's Manual - Page 12

A CAUTION: Sitting ina reclined position when your vehicle is in motion can be dangerous. Even if you buckle up, your safety belts can't do their jobwhen you're reclined like this. The shoulder belt can't do its because it job won't be against your body. Instead, itwill be in front of you. In a crashyou could go into it, receiving neckor otherinjuries. The lap belt can't do job either. In a crash the its belt could go up over your abdomen. The belt forces would be there, not at your pelvic bones. This could cause serious internal injuries. For proper protection when the vehicle isin motion, have the seatback upright. Then sit well back in the seat wear your safety and belt properly. Head Restraints Slide the head restraint up or down so that the topof the restraint is closest to the top your ears. This position of reduces the chance ofa neck injury in a crash. The head restraints tilt forward and rearward also. 1-5