It is normal for babies to sleep with their hands outside without getting cold because the capillaries of infants and young children are relatively thin, so the blood circulation function is poor, often leading to a lower temperature of the skin. If the outside temperature is low, letting the baby’s hands outside the nest for a long time will lead to temperature changes and cause the phenomenon of getting cold. However, if protective measures are taken in time, short-term exposure will not cause the occurrence of cold symptoms, and attention should also be paid to indoor ventilation to reduce the amount of bacteria and viruses in the air. In addition, you should also take your baby to the sun and outdoor sports regularly, which can effectively strengthen the immune system.