After 2 years of prolonged hypothermia, the cause cannot be found out. Dynamic observation of body temperature, stopping medication and expanding the scope of examination should be adopted to further find out the cause: 1. Record the temperature and symptoms: patients can also measure the temperature more than three times a day, record the temperature and symptoms, observe the dynamic changes in temperature, in the follow-up convenient to hand over to the doctor to check, and listen to the doctor’s advice. 2. Drugs: The cause of hypothermia may be related to drugs, so stop the medication and go to the hospital for a checkup to see if there is still hypothermia. 3. Expanding the scope of examination: If the cause is not found in the examination, the patient should expand the scope of examination under the guidance of the doctor to exclude functional hypothermia, and should continue to have regular examination. Patients should not use drugs indiscriminately when the cause of the disease is not clear, to avoid causing adverse reactions, and should use drugs under the guidance of the doctor and symptomatic treatment.