What are the Disadvantages of a Medical Thermometer?

Medical thermometers measure body temperature and provide this critical information to individuals, caregivers and medical professionals. In the 21st century, we have a variety of medical thermometers from which to choose. However, not all of them yield the same degree of accuracy. Further, the design of some thermometers presents safety concerns. When selecting a thermometer, consider the unique circumstances of the situation, including the patient, and choose the best one for those circumstances.

Mercury Hazards

• Glass thermometers work because the mercury encased in them expands and contracts as body temperature rises and falls. If you dispose of a thermometer with mercury without regard for its toxicity, serious health and environmental consequences could result. Similarly, a broken glass thermometer could release the liquid mercury, as well as harmful vapors into the air.

  Mercury spills in the environment could end up in water and contaminate fish and other wildlife. When mercury contaminates certain fish, they convert it into methylmercury, an especially toxic form. Pregnant women should not eat certain fish known to have relatively high levels of methylmercury. In addition, all people must be wary of how often and which types of fish they consume. The EPA publishes a list of fish known to have unsafe levels of methylmercury.

  A spill of mercury in a doctor's office, school or home environment poses significant health hazards. Exposure could result in serious damage to kidneys, lungs, brain, heart and the immune system.

  Discard glass thermometers according to the recommendations of your local health department. Do not throw a glass thermometer into the trash.

Digital Delays

• Doctors recommend using digital thermometers, especially for babies. When you take a baby's temperature with a digital thermometer, do so rectally. Adults can use digital thermometers orally or under the armpit. For children under 3, oral and tympanic thermometers do not provide the same accuracy as the rectal ones.

  Digital thermometers provide accurate readings without the risk of any hazards from mercury. However, digital thermometers have a time delay of one minute. This delay could be problematic for a fussy infant or toddler running a fever. Try to keep the child calm and distracted with a toy, book or favorite blanket.

Tympanic Unreliability

• Tympanic thermometers function by infrared radiation and a thermopile detector that measure the temperature of the tympanic membrane or eardrum. This method is quick, but the reliability of the results varies. The general public should use it as a screening tool, but allow medical professionals to make the final judgment as to the significance of a fever. The clinical ear thermometer used in doctors' offices has greater accuracy than those available to the public. Part of the discrepancy concerns the proper use and positioning of the thermometer.