3. Installing the car seat or buckling up your child the wrong way

Before you install a car seat, read the seat maker's instructions. Also read the section on car seats in your car's guidebook. Make sure the seat is tightly secured. To check, grab the bottom of the seat near the attachment points. If you can move the seat more than 1 inch (2.5 centimeters) from side to side or front to back, that means it's not secured tightly enough. Also make sure that the seat faces the correct way.

If you use a seat that's only for infants or a convertible seat that faces the back of the car, keep these tips in mind:

• Use the harness slots described in the car seat's instruction guide. The slots are usually located at or below the child's shoulders. Place the harness straps over your child's shoulders.
• Buckle the harness straps and chest clip. Make sure it's a snug fit. The chest clip should be even with your child's armpits. Make sure the straps and clip lie flat against your child's chest and over their hips with no slack. If you need to, place tightly rolled small blankets alongside your baby for head and neck support. If the car seat maker allows, place a rolled washcloth between the crotch strap and your baby to make a safer fit.