A normal body temperature of a baby is between 36,5 en 37,5 degrees Celsius. There is some play here, depending on the ambient temperature, how warmly the baby is dressed, etc.
The first days you are advised to measure your baby’s temperature. Sometimes the baby can cool off somewhat after the birth; he or she needs be dressed warmly and sometimes a hot water bottle is required to get back to the right temperature.
A hat is then very important, because your baby loses a lot of heat via the head. How you should dress your baby and how many blankets your baby needs, depends on the ambient temperature. A baby should also not be too hot. A sweating baby is not good. This is why you take the weather and the room temperature into account.
The baby has a fever if its body temperature is above 38 degrees Celsius. It is best to measure this rectally in a baby. If a baby under three months has a fever, you must always contact a doctor. The only exception to this is the first 48 hours after vaccination.
In babies, a temperature of under 36,5 degrees can also be a sign of illness. This is also a reason to contact a doctor.