Young children repeated low fever triggers more, such as upper respiratory tract infection, tuberculosis, leukemia, etc., generally do not more than three days, more than three days recommended timely medical treatment, to avoid delaying the condition. 1. Upper respiratory tract infections, most of the fever induced within three days can return to normal, if there is a recurrence of low fever or low fever persists, need to be alert to the possibility of complications. 2. Tuberculosis, which can be characterized by prolonged recurrent low-grade fever, mostly in the afternoon, can be combined with other symptoms, such as coughing and exertion. 3. Leukemia can also be repeated low fever as the first symptom, other physical symptoms can be atypical, antibiotics and other treatments are ineffective, and the corresponding special examination is needed to clarify the diagnosis. If a young child has recurrent low-grade fever for more than three days without improvement, it is recommended to consult a doctor in time to find out the cause and follow the doctor’s instructions for symptomatic treatment to avoid delaying the condition.