There are other kinds of medical thermometers : tympanic thermometers test the temperature of the tympan ( the eardrum ) with infrared ; band thermometers test a person 's temperature on the front of their head . Thermometers are used in the production of candy . Medical thermometers such as mercury-in-glass thermometers , infrared thermometers , pill thermometers , and liquid crystal thermometers are used within health care to determine if individuals have a fever or are hypothermic .