A fever of 39.1 degrees in a 1-year-old child may be caused by accumulation of food, or it may be caused by other diseases such as upper respiratory tract infection and intracranial diseases. Accumulation of food is common in infants and young children, mostly due to improper diet and other reasons, can be manifested as abdominal distension, abdominal pain, anorexia, nausea, vomiting, fever, etc., you should promptly go to the hospital for consultation and examination, according to the results of the examination and the signs and symptoms, in order to determine whether it is an accumulation of food caused by the fever of infants. Other diseases such as upper respiratory tract infections, blood diseases such as lymphoma and leukemia, connective tissue diseases such as systemic lupus erythematosus and dermatomyositis, skin diseases such as generalized dermatitis, and intracranial diseases such as cerebral contusion can lead to fever of 39.1 degrees, which need to be examined and identified for better treatment. A 1-year-old baby with a fever of 39.1 degrees needs to be actively consulted to clarify the cause of the disease and then targeted treatment.