Body temperature for a while 35.5 ℃ for a while 36.8 ℃ the main reasons are: environmental factors, physiological factors, measurement tool errors. 1. Environmental factors: the human body temperature and the external environment has a certain relationship, if the external environment is too low, the body will reduce heat dissipation, the body surface temperature will be relatively low; if the external environmental temperature is higher, or thicker clothing, the human body will increase the heat dissipation, the body surface temperature will be relatively high. 2. Physiological factors: the human body in a quiet state, the body’s metabolic rate is relatively low, producing less heat, the body temperature will be lower; if strenuous exercise, or in a state of tension, anxiety, etc., the body’s metabolic rate is higher, the body temperature will rise. 3. Measuring tool error: If the tool for measuring body temperature is not produced by the regular manufacturers, there may be a large error in the measurement process, and the body temperature will be 35.5℃ for a while and 36.8℃ for a while. The above situation, we must closely observe the body temperature, if the body temperature exceeds 37.2 ℃, it is a fever, we must consult a doctor in time to identify the cause, according to the cause of fever targeted treatment.