Generally, after eating, the basal metabolic rate will increase, causing a slight increase in body temperature. A body temperature of 37.3℃ may be normal and does not necessarily mean that the patient has a fever. Therefore, it is not recommended to measure the body temperature just after eating, and it is better to measure the body temperature half an hour after the meal. If the body temperature is lower than 37℃ belongs to normal body temperature, if the body temperature is still 37.3℃ measured half an hour after meal belongs to febrile patients and is hypothermic. Normally, to measure the temperature, we should pay attention to avoid taking temperature immediately after eating hot and cold water or strenuous exercise, diet, sunbathing or swimming, and measure the temperature in a calm state indoors. In addition, there will be a slight increase in body temperature in the afternoon and a slightly lower body temperature in the morning, and a slight increase in body temperature in women during menstruation or pregnancy.