Types of Thermometers to Use for Adults

Fevers in adults are not usually dangerous unless they reach 102 degrees Fahrenheit or higher. They are a natural response to infection or an indicator that something else is wrong in the body. But the only way to know when fever should become a serious concern is to monitor it using a thermometer. There are three common types of thermometers used on adult patients either at home or in the doctor's office.

Oral

• The standard oral thermometer is the device most adults today grew up with. This device's bulb is placed under the tongue and held in place for a specific amount of time. Usually three minutes is adequate, according to the Mayo Clinic website. In older styles thermometers the bulb was attached to a glass rod with mercury inside that would climb to indicate the temperature of the body. Newer models use digital technology to read the temperature faster and just as accurately.

  These same thermometers are also used for taking axillary temperature, which is less accurate but easier for some people. Place the bulb under the armpit and hold it in place for the required amount of time.

Tympanic

• A tympanic thermometer is a device that can be used on adults and children. The tympanic version is very useful in taking temperatures of the elderly and small children who are less able to cooperate with an oral measurement. The thermometer works by inserting the sensor tip of the device into the ear. With the press of a single button the thermometer returns a digital reading within a second or two. This fast procedure is hardly noticed by those it's used upon.

  Tympanic thermometers work by detecting the temperature of the tympanic membrane inside the ear through infrared radiation from the tissue itself. Although they work quickly and are relatively accurate, the Consumer Reports website reports that these types of thermometers are less accurate and more costly than oral versions.

Forehead

• Forehead thermometers are the latest in the evolution of temperature taking products. These are available for consumer use, but are more often found in doctor's offices today. These devices, also known as temporal scanners, work by detecting infrared radiation directly from the forehead. The user presses a button and swipes the sensor across the skin of the forehead once and checks the reading. It is quick and simple to use.

  The drawbacks of these types of thermometers are the high price of around $50, as of December 2010, a lack of precision and a more fragile product, according to the Consumer Reports website.