Three-year-old baby night sleep sweating is generally considered to be too high room temperature, vitamin D deficiency and other factors. 1. Room temperature is too high: because the three-year-old baby’s thermoregulation function has not yet fully developed, if the room temperature is too high or the baby wears too thick, wrapped too tightly, will be easy to cause sleep sweating. You can reduce the baby with clothing or use air conditioning to help reduce the room temperature. 2. Vitamin D deficiency: three-year-old baby is the period of rapid physical development, if the lack of vitamin D, the body of calcium, phosphorus absorption and utilization is insufficient, will be manifested in the night sleep sweating. In addition, other causes can also lead to three-year-old baby night sleep sweating, such as infant hypoglycemia, active rickets and so on. Parents are advised to bring their babies to the doctor in time to clarify the cause of the disease and follow the doctor’s advice to do the appropriate treatment.