The infrared thermometer is most accurate when measuring the inner wrist of both hands, because the inner wrist of both hands is least affected by the temperature of the external environment, and therefore the temperature of the body occurs with the least error. In addition, human body temperature is regulated by the hypothalamus thermoregulatory center, and through the process of heat production and heat dissipation to achieve balance, human body temperature will fluctuate in the normal range. Once the body temperature becomes abnormal, it is recommended to go to the hospital promptly for symptomatic treatment of the cause.