What safety checks should I perform after securing my child in the car seat?

Make sure the top of the child's head is at least 1 inch (2.5 cm) below the top of the head support. Check that harness straps are not twisted. Verify the harness is snug by confirming you cannot pinch any slack in the straps—they should lie in a relatively straight line without sagging. The chest clip must be positioned at armpit level.