Chevrolet 2003 S10 Pickup Owner's Manual page 14

Head Restraints
Sitting in a reclined position when your vehicle
is in motion can be dangerous. Even if you
buckle up, your safety belts can't do their job
when you're reclined like this.
The shoulder belt can't do its job because it
won't be against your body. Instead, it will be
in front of you. In a crash you could go into it,
receiving neck or other injuries.
The lap belt can't do its job either. In a crash
the 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 is in
motion, have the seatback upright. Then sit
well back in the seat and wear your safety belt
properly.
Head restraints are fixed on some models and
adjustable on others. Slide an adjustable head restraint
up or down so that the top of the restraint is closest
to the top of your head. This position reduces the
chance of a neck injury in a crash.
1-7