The crib is the only infant product in which a consumer, such as a parent or caretaker, is encouraged to leave the infant unattended, usually alone in the bedroom, while the infant is sleeping or going to sleep or waking. Given frequent falls from the crib, federal crib regulations have set the minimum distance between the top of the mattress support and top of the crib side rail as 26 in. and this height must include a 6-in. thick mattress. When a mattress is used with the crib, the actual height of the crib side as a barrier is 20 in. These crib regulations also require instructions for the caretaker to discontinue using the crib when the child's height is 35 inches. These federal crib regulations attempt to create an escape-resistant sleeping environment for all children who are less than 35 in. tall. Of 144 children between the ages of 12.5 and 36.5 mo. observed while attempting to climb out of a crib, who also had standing heights of less than 35 in., many were able to climb from cribs with side rail heights of 26 in. When the crib side-rail height was raised beyond the minimum of 26 in., the frequency of children climbing over the crib rails decreased.