A recent comprehensive review of peer reviewed published evidence noted that hypoxia has frequently been associated with significant defects in cognition. In some studies changes in cognitive function were seen with even mild levels of oxygen desaturation. Such changes were observed in all groups except premature babies. The young child may be relative resistant, as their physiology is adapted for the relatively hypoxic intrauterine environment. However a recent study also suggests that premature infants may also have problems. Thus a cautious approach has been adopted where children who fail to maintain adequate oxygen saturation while placed in the car seat are discharged in a car bed.