These are examples of commonly used thermometers.

• Ear thermometers use infrared energy to measure body temperature. The small cone-shaped end of the thermometer is placed in the ear, and body temperature shows on the digital display. The results appear within seconds. Some models also show the corresponding oral and rectal temperature readings.
• Electronic thermometers have a temperature probe at one end and a digital display window at the other end. They work by measuring how well electricity travels through a wire in the probe. Heating or cooling of the probe changes the flow of electricity. This change is converted into a temperature value that shows in the display window. Electronic thermometers can be used in the mouth, armpit, or rectum.