How to buy a thermometer
A thermometer buying guide
When you or your loved ones begin to feel warmer than normal, along with other symptoms of illness, monitoring body temperature is an important way to track health. While figuring out which thermometer to buy, consider the type of thermometers you'll need, the types of displays available and how you want to take temperature.
>> Consider the types of thermometers
You'll need to make a comparison of the thermometer types listed below before you shop for your next thermometer to ensure that you'll know the best thermometers to buy for your needs.
Liquid-filled thermometers are the oldest and most well-known type of thermometer. Typically, the bulb of the liquid thermometer is placed in the area where temperature is to be measured and left for three minutes to get a good reading. There are two types of liquid-filled thermometers:
- Mercury: Accurate and durable, but harder to read than other types, and the mercury in the thermometer can be harmful if the thermometer breaks.
- Alcohol: Inexpensive, durable and easier to read than mercury-filled models, plus safer due to the non-toxic contents.
Digital thermometers allow for quick temperature readings displayed on an LCD screen. They are quickly becoming the most popular type of thermometer due to the multiple thermometer designs available:
- Mouth: This type of thermometer is usually less expensive in comparison with others and comes in a variety of thermometer designs.
- Infrared: Temperature can be obtained in 2-3 seconds by lightly touching the body, making it a good option for infants and toddlers. A common type of infrared thermometer is the in-ear design, requiring only 2-3 seconds to register a temperature, which makes it a good choice for infants and children. The newly-developed temporal artery thermometer is even less intrusive. It works as you gently swipe the thermometer across someone's forehead and can even be used while he or she is sleeping. Although this is an excellent choice for infants and children, prices are currently much higher than in-mouth digital thermometers.
- Pacifier: This type of thermometer design resembles a baby's pacifier and can easily take the temperature of an infant without disturbing him or her with an unfamiliar and intrusive device.
Though this thermometer style has the advantages of being inexpensive and quick to use, electronic thermometers must be re-calibrated to ensure accuracy.
A basal thermometer measures small changes in a person's base body temperature, so its display is more precise than other types of thermometers. Designed to chart a woman's ovulation cycles for family planning, a basal thermometer has a restricted temperature range of 96-100° F. There are two types of basal thermometers:
- Liquid-filled — very accurate and reliable
- Digital: offers quick results, and you can store temperatures in the thermometer's memory for later comparison.
Single-use disposable thermometers are available to reduce the risk of cross-contamination in a clinical setting. There are several different types of disposable styles, from in-mouth to "wearable" thermometers that stick to the forehead and easily peel off after use. "Wearable" thermometers are are great for children, since they're not invasive and resemble the familiar band-aid.
>> Consider multiple thermometers
If you have a family with a wide spread of ages, you might want to consider buying multiple thermometers. The thermometer that works well for you will probably not be appropriate for taking the temperature of a six-month-old baby. Consider this while everyone's healthy to avoid the added stress of this buying decision when you or your loved ones are ill.
>> Summary of thermometers
The thermometer comparison chart below summarizes the different types of thermometers by where in the body you take the temperature.
|Mouth ||Oral (liquid-filled or digital) ||Reliable readings |
|Rectum ||Rectal (liquid-filled or digital) ||Most accurate readings |
|Ear ||Infrared ear thermometer ||Not as intrusive as oral models |
|Armpit ||Basal ||Appropriate temperature range for intended use |
|Forehead ||Infrared (temporal artery) ||Least intrusive |
>> Understand what is a healthy temperature
Although the standard human healthy temperature is 98.6° F (37° C), people will vary. Take your and your family's temperatures a few times when everyone's healthy, so that you get a sense of what's normal for each person.
>> Think about proper care of your thermometer
Be sure to store your thermometers properly to keep them working accurately. It's important to store the thermometer with a sterile cover over the probe (the part that touches the body), regardless of what design or style the thermometer is. Also be sure to sterilize the thermometer with rubbing alcohol after use. Store thermometers at room temperature in an environment away from heat and light. When you get rid of mercury-filled thermometers, treat them as hazardous waste, and take them to an appropriate hazardous waste disposal facility, if available. Calibrate digital thermometers regularly (if the unit allows for it) to ensure continued accuracy.