Baby growing up with a fever of 39℃ is an abnormal situation, which may have occurred periodontal infection and needs to be paid attention to and treated in time. Normal infants and children have a basal body temperature of 36.9℃-37.5℃ and a temperature of 39℃ or more in case of high fever. Usually children do not have fever when they are teething, and even if some children have fever when teething, it rarely exceeds 38℃. If a child has a fever during teething, there may be an infection. Because the gums are more fragile during teething, if there is milk tartar or food residue stuck on them and not cleaned in time, it can easily breed bacteria and cause infection and fever symptoms. When the body temperature continues to rise to 39 ℃, it is a high fever state, which is more dangerous and may cause febrile convulsions, resulting in brain damage, you need to take your baby to the pediatric department of the hospital in time to conduct relevant examinations, according to the results of symptomatic treatment. During the teething period, babies need to maintain good oral hygiene and clean up food residues in time to avoid breeding bacteria.