Sudden high fever of dolls may be caused by upper respiratory tract infection, toddler’s emergency rash, Kawasaki disease and so on. 1. Upper respiratory tract infection: the common pathogens of this disease are viruses, only a few are caused by bacteria, different pathogens lead to infection, will show different symptoms, which will lead to the doll suddenly high fever, accompanied by sore throat, cough, chills, headache and other symptoms. 2. Early childhood emergency rash: the disease is a common rash infectious disease in infancy and early childhood, which will lead to a sudden high fever in children, and the main clinical manifestations are fever, skin rash and other symptoms. 3. Kawasaki disease: the disease is mainly related to infection, immune factors, genetic factors, resulting in children with a sudden high fever, accompanied by skin rashes, mucous membrane congestion, lymph node swelling and other typical symptoms. Dolls suddenly high fever, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.