Newborns within 28 days of birth belongs to the perinatal period, the child has just been separated from the mother’s body, is the transition period of self-adaptation to the external environment, this time is easy for infants to suffer from diseases, and the mortality rate is the highest period of time. So within 28 days of the newborn if there are no special circumstances, it is best not to go out, because the temperature and humidity at home is more stable, relatively few pathogens, so it is safer at home. After the child is full moon and gradually grows up, he or she gradually adapts to the outside environment, and also needs to breathe fresh air outside and get sunshine. So the child 2-3 months of age, in good weather under the premise of parents can take the child out, enjoy nature, sunshine, but a single time is not too long.