Mercury-containing glass thermometers are no longer recommended because of safety concerns. If you have one in your home, consider replacing it with a digital electronic thermometer.

Digital electronic thermometers are accurate, easy to read, and durable. Temperature strips are very convenient and safe but are not as accurate as digital thermometers and should only be used to measure armpit (axillary) temperature. They are inaccurate when used on the forehead. Thermometers that measure the temperature in the ear are fast, easy to use, and quite accurate, but they are expensive.

Rectal thermometers with enlarged bulbs are helpful for children younger than 6 or anyone who cannot hold an oral thermometer in his or her mouth. For more information on how to take a temperature, see the topic Body Temperature.