Low fever refers to a body temperature between 37.4-38.1, or parents measure the child’s body temperature is slightly higher compared to the normal state. The common causes of hypothermia are: 1. acute upper respiratory infection caused by viral infection, the child has fever, runny nose, etc., the mental state is relatively good, oral anti-fever and antiviral drugs for about 1 week can be cured. 2. acute gastroenteritis caused by improper diet, the child has fever, nausea, vomiting, diarrhea, the temperature is not high, symptomatic solution to the gastrointestinal problems body temperature can be receded. Uncommon are: 1. Rheumatic fever and tuberculosis caused by streptococcal and tuberculosis infections, the child will have low fever, which will be accompanied by weakness, excessive sweating, night sweats, cough and swollen lymph nodes. 2. Hematologic diseases can also lead to the appearance of hypothermia. 3. Connective tissue diseases, such as systemic lupus erythematosus, can also lead to the appearance of hypothermia. 4. Tumor diseases, such as pituitary tumors, malignant lymphomas, etc.