Why Mercury Thermometers Are Being Replaced

Thermometers measure temperature with substances that react to heat and cold in some way. There are two standard temperature measurements used with thermometers. The measurements are Fahrenheit and Celsius. The first thermometers were called thermo scopes and were claimed to have been invented by several different people. However Santorio Santorio, an Italian inventor, was the first one to put a numerical scale on one. The first mercury thermometer was created in 1714 by Gabriel Fahrenheit. He is responsible also for the temperature scale that bears his name.

In the mercury thermometer, used for a very long time to measure an individual’s body temperature, the material (mercury) expands when it becomes warmer and retracts when it cools.

Body temperature is indicative of many body processes. The most common one is fever, which may result from many different causes. Whatever the cause, it is an indicator that something out of the ordinary is going on in the body. It typically is not considered dangerous unless it reaches 103 F or higher. Mothers are very aware of the temperatures of their young children and infants because it’s the first symptom of illness.

Medications to lower the temperature can be purchased over the counter. However, it may be better to let it go untreated. Fever may play an important role in helping the body fight off infections. However, the patient may be very uncomfortable with the fever and may wish some relief from the pains and discomforts it causes.

A major change took place in medical thermometers in the 1990s. The mercury-based thermometers presented risks that sometimes resulted in injury. For example, they are easy to break since they’re made of glass and must be shaken sharply to reset them. When they break, the mercury that spills is poisonous. They have been largely replaced nowadays with electronic digital thermometers.

In a few cases, thermometers with liquids other than mercury have replaced the originals. Heat-sensitive liquid crystals were used in some, for instance. Other options are digital infrared contact or non-contact thermometers.

Most medical thermometers are used to test oral, rectal, or vaginal temperatures. Checking the temperature orally is only possible if the patient can hold the thermometer in the mouth in the proper place and securely. Children are unable to do this as are some patients who are too weak, are coughing, or are vomiting. The new digital thermometer reacts very quickly, so they can often be used in patients where the typical mercury thermometer cannot be held in the mouth for an extended length of time.



Rectal temperature is the most accurate measure of body temperature; however, for various reasons it is used only when absolutely necessary. Even so, it’s the method of choice for infants.

A list of modern thermometers with a link to an example of each type is displayed below:

• Digital Ear Thermometers


• Digital Instant Read Thermometers


• Digital Oral Thermometers


• Digital Rectal Thermometers


• Clinical Thermometers


• Hospital Thermometers and Probe Covers


• Digital Medical Thermometer

These new modern electronic thermometers are efficient and fast. Many are able to return accurate temperture measurements in just a few seconds. In fact, the new Invacare Instant Ear Thermometer takes temperature readings in just one second! This digital thermometer has surface scan ability and costs less than $30.00. It includes a signal tone indicating peak temperature and fever alarm.

Another popular thermometer is the Tempa-Dot Thermometer. This disposable thermometer is soft and flexible for oral and axillary use. It comes individually wrapped and is intended for single-use. This disposable thermometer accurately assesses infants, pediatric, children and adult temperatures in 60 seconds.

Vitality Medical has a wide range of body thermometers at very competitive prices. Go to the web site to explore the new thermometer options and to update your old mercury thermometer.