The use of gallium as a thermometric agent makes the thermometer safe and reliable for use in humans. Generally, the thermometer has an easy-to-read scale, allowing the user to quickly identify the indicated temperature. To measure body temperature, place the end of the thermometer under the tongue (oral), in the armpit (axillary), or in the rectum (rectal). , according to the manufacturer's instructions. Wait a few minutes for the thermometer to read and record the temperature.