Human body temperature is different in the morning and evening, because the body temperature has circadian rhythm changes, but also susceptible to fluctuations due to the effects of exercise, eating and so on. Normal human armpit temperature is 36～37℃, rectal temperature is 36.5～37.7℃, and normal oral temperature is 36.3℃～37.2℃. Usually the body temperature is different in the morning and evening, because there is a circadian rhythm in body temperature. Generally low temperature at night, high temperature in the morning, but the morning and evening body temperature relative to the afternoon body temperature, it is on the low side. Since the body temperature is also susceptible to seasonal, exercise, eating and other factors, so the specific value is not fixed, but usually within the normal range mentioned above can be without excessive worry. If there is a big difference between the morning and evening temperatures, or if the body is accompanied by other uncomfortable symptoms, it is necessary to consult a doctor in time. For those with abnormal body temperatures, you can closely monitor the changes in body temperature on a daily basis. If you measure the temperature of the armpit, you need to use a towel to wipe the armpit before measurement to prevent the mercury thermometer from slipping off. Avoid strenuous exercise and drinking hot water before temperature measurement.