GMC 2012 Terrain Owner's Manual page 93

WARNING
Children can be seriously injured
or strangled if a shoulder belt
is wrapped around their neck
and the safety belt continues to
tighten. Never leave children
unattended in a vehicle and never
allow children to play with the
safety belts.
Airbags plus lap shoulder belts
offer protection for adults and older
children, but not for young children
and infants. Neither the vehicle's
safety belt system nor its airbag
system is designed for them. Every
time infants and young children ride
in vehicles, they should have the
protection provided by appropriate
child restraints.
Children who are not restrained
properly can strike other people,
or can be thrown out of the vehicle.
WARNING
Never do this.
Never hold an infant or a child
while riding in a vehicle. Due to
crash forces, an infant or a child
will become so heavy it is not
possible to hold it during a crash.
For example, in a crash at only
40 km/h (25 mph), a 5.5 kg (12 lb)
infant will suddenly become a
110 kg (240 lb) force on a person's
arms. An infant should be
secured in an appropriate
restraint.
Seats and Restraints 3-39