A body temperature of 37.5°C is considered to be a low-grade fever. A variety of infectious and non-infectious diseases can cause fever, and it is necessary to identify the causes of elevated body temperature and make targeted treatment. There are many causes of elevated body temperature, common infectious factors such as colds, pneumonia, appendicitis, pancreatitis, cholecystitis, etc., need to clarify the cause of the disease and specific causative factors through routine blood tests, chest X-ray, abdominal ultrasound and other tests, targeted anti-infective treatment. In addition, rheumatism, connective tissue disease, tuberculosis, tumor disease, etc., can also cause symptoms of low fever, but mostly persistent low fever. If the body temperature is normal people suddenly fever without too much panic, can be adjusted by physical cooling, if not improved, and the body temperature continues to rise or poor mental state, it is recommended to consult a doctor in a timely manner.