A person’s normal basal body temperature is supposed to be higher than 36°C, and 35.5°C is supposed to be abnormal. However, in clinical practice, there is a group of people whose body temperature is also often lower than 36℃ or higher than 37℃, but without any clinical manifestations. There is another situation, if the temperature is measured after sweating, or the surrounding environment is cold, then it may also be lower than 36℃, such hypothermia, clinically defined as physiological abnormal temperature, belongs to the normal phenomenon. If the body temperature is 35.5℃, accompanied by some clinical symptoms, such as chills, reduced appetite, or memory loss, these symptoms, the most common clinical hypothyroidism, the basal body temperature will also be lower than 36℃, if the basal body temperature is below 36℃, it is recommended to go to the hospital for further examination to clarify.