GMC 2007 Sierra 1500 Pickup Owner's Manual page 48

CAUTION:
{
People should never hold a baby in their
arms while riding in a vehicle. A baby
does not weigh much — until a crash.
During a crash a baby will become so
heavy it is not possible to hold it. For
example, in a crash at only 25 mph
(40 km/h), a 12 lb (5.5 kg) baby will
suddenly become a 240 lb (110 kg) force
on a person's arms. A baby should be
secured in an appropriate restraint.
48