1 A normal temperature range for a child is usually up to 38°C. 2  Fever is usually a sign of infection in the body. 3  Fever is often caused by a virus and sometimes by bacteria. The normal temperature range is up to 38ºC. 2  Fevers are common in children. 3  If your child seems well and is happy there is no need to treat a fever. 4  If your child is under three months and has a fever above 38º C, take them to the doctor to be checked.