The normal human body temperature, oral temperature is generally 35.8-37.4°C. In a normal state, the body temperature of a normal person should not be higher than 37.5°C. If it is often higher than 37.3℃, it is hypothermia. According to the body temperature condition, fever is classified as:low fever:37.3-38℃; moderate fever:38.1-39℃; high fever:39.1-41℃; ultra-high fever:41℃ or more. The body temperature of normal people is not completely uniform, usually lower in the morning and higher in the afternoon. It is lower in winter and higher in summer; women also have a slightly higher body temperature before menstruation and during pregnancy. However, these are not within the range of hypothermia, but are normal physiological changes. There are many causes of hypothermia, such as chronic purulent tonsillitis, chronic paranasal sinusitis, chronic biliary tract infection, chronic urinary tract infection, chronic pyelonephritis, chronic infectious diseases such as extrapulmonary tuberculosis, hepatitis without xanthogranuloma, prolonged hepatitis, chronic hepatitis and cirrhosis, rheumatoid arthritis disseminated lupus erythematosus, and hyperthyroidism. Patients with this type of hypothermia are those with organic diseases. In addition, hypothermia often occurs in people with a weak constitution, or after illness. If hypothermia is accompanied by symptoms of vegetative dysfunction: hand tremors, flushing of the face, tachycardia, hiccups, abdominal distension, insomnia, it may be neurogenic hypothermia. The term “hypothermia” in Chinese medicine also includes the patient’s subjective self-consciousness of heat in the hands and feet and heat in the chest, but the body temperature is not higher than normal. The common manifestations are night fever and morning coolness, or night fever, afternoon hot flashes, hot hands and feet, bone evaporation, often accompanied by signs and symptoms such as emaciation, fatigue, fatigue, anorexia, irritability, red tongue with little coating, and fine pulse. Modern medicine has divided the causes of this disease into two categories: infectious and non-infectious. Common causes of long-term hypothermia (lasting more than 2 weeks) include pediatric tuberculosis and extrapulmonary tuberculosis; chronic infectious lesions (such as chronic tonsillitis, chronic paranasal sinusitis, chronic gingivitis, chronic otitis media, chronic nephritis, tumors, necrotic tissue resorption, fungal infectious pneumonia, tuberculosis, etc.); and functional hypothermia, characterized by normal body temperature in the early morning and hypothermia after activity, including drug fever. Based on the clinical manifestations, it is not difficult to diagnose those with hypothermia as the main symptom. The key is to find out the cause of the disease and examine the cause and treatment. Modern medicine mainly adopts the method of eliminating the cause of the disease. According to traditional Chinese medicine, fever can be caused by external evil attacking the human body and by the struggle between positive and evil; fever can be caused by diet and fatigue, emotional and mental stagnation, persistent food, phlegm and blood stasis, resulting in dysfunction of internal organs, loss of qi, blood, fluid and yin and yang. In cases of this disease, there are generally more internal injuries than external sensations.