MODEL RELEASED. Digital tympanic thermometer, in the ear of a young boy. It is a modern version of the traditional glass, mercury-filled thermometer. Body temperature is more usually measured from the mouth, armpit or rectum. This design allows measurement, with minimal discomfort, from babies and children. It is used to record & store records of body temperature, and uses an electronic probe connected to a digital readout display. Body temperature is under the control of the hypothalamus area of the brain and is maintained at 37 degrees Celsius.