High and low body temperature is not good for human health, usually there are several factors as follows: First, the most common factor is endocrine disorder, the most common organ is impaired thyroid function, in hyperthyroidism there will be an increase in body temperature, in hypothyroidism there will be a decrease in body temperature, so if the thyroid gland is dysfunctional, there will be a high and low body temperature occurrence. Second, the hypothalamus central temperature control system is damaged, in the hypothalamus by severe impact, such as acute traumatic brain injury, acute cerebral hemorrhage, stroke, cerebral infarction, cerebral embolism, etc., in the hypothalamus temperature perception center is damaged, will also appear in the clinical symptoms and performance of sudden high and low body temperature. Third, in infectious diseases, such as inflammatory infections, there will be recurrent episodes of thermogenic sources in the body, and the therapeutic response of the thermogenic source will produce sudden high and low body temperature.