Medical thermometer

A medical/clinical thermometer showing the temperature of 38.7 °C

Medical thermometers are used for measuring human body temperature, with the tip of the thermometer being inserted generally into the mouth (oral temperature).

Classification

Traditional

The traditional mercury thermometer consists of a mercury-filled bulb attached to a small tube. There is a constriction in the neck close to the bulb. As the temperature rises, the force of the expansion pushes the mercury up the tube through the constriction. When the temperature falls, the column of mercury breaks at the constriction and cannot return to the bulb, thus remaining stationary in the tube. To reset the thermometer, it must be swung sharply.

When it is designed for use in humans, the typical range of this kind of thermometer is from about 89.6°F to 109.4°F or 35°C to 42°C. The temperature is obtained by reading the scale inscribed on the side of the thermometer.

Digital thermometer

Digital

Recently, mercury-based thermometers were found too risky to handle and have largely been replaced with electronic digital thermometers, etc.

Disposable

To eliminate the risk of patient cross-infection, disposable single-use clinical thermometers and probe covers are employed in clinics and hospitals.

Location

Oral

Oral temperature may only be taken from a patient who is capable of holding the thermometer in their mouth correctly and securely, which generally excludes small children or people who are overcome by coughing, weak, or vomiting.

Underarmpit

Under the armpit (axillary temperature),

In to the rectum

Into the rectum via the anus (rectal temperature).