If the patient has been experiencing hypothermia usually for several reasons as follows: First, the most common cause is infectious factors, bacteria, viruses, fungi and other pathogenic microorganisms, such as mycoplasma or chlamydia infections, will appear when the body temperature has been hypothermic. At this time, because the above-mentioned infectious factors produce inflammatory mediators in the body, the inflammatory mediators will release endogenous pyrogenic sources, resulting in a situation where the body appears to be hypothermic all the time. Secondly, connective tissue diseases can also lead to hypothermia all the time, such as dermatomyositis, systemic lupus erythematosus, dry syndrome, etc. The above diseases can also lead to hypothermia all the time. There are also some rheumatic diseases, such as rheumatoid arthritis and rheumatoid arthritis, which can also lead to hypothermia all the time. Thirdly, diseases with extremely low immunity, such as severe anemia, thyroid dysfunction or tumor disease, cancer of the blood system, AIDS, etc., may cause hypothermia all the time.