Underarm sweat is generally lower than normal, because underarm sweat is due to sweat pores as well as sweat glands secrete liquid, under normal circumstances will be through the evaporation of the body surface of the heat away and play a role in cooling. If you put the sweat on the thermometer, the sweat on the surface of the thermometer will take away the heat when you measure the temperature, thus making the thermometer readings appear low. Therefore, you should take a towel or paper towel to wipe the sweat in the armpits well before measuring the temperature. In addition, the thermometer and the armpits should be in contact with each other for more than 10 minutes for the temperature to be relatively accurate, so it is recommended to measure the temperature when the armpits are not sweaty.