The American Academy of Pediatrics says to "make sure the seat is at the correct angle so your infant’s head does not flop forward. Many seats have angle indicators or adjusters that can help prevent this. If your seat does not have an angle adjuster, tilt the car safety seat back by putting a rolled towel or other firm padding (such as a pool noodle) under the base near the point where the back and bottom of the vehicle seat meet." Safety seats come with an instruction booklet with additional information on the appropriate angle for the seat.