Modern digital thermometers are quick, safe and accurate
Today's digital thermometers are fast, easy to use and safer
than traditional mercury thermometers. That said, most of them are made of
cheap, mass-produced plastic and have a poor reputation for durability, so
consider keeping an inexpensive spare on hand or planning to replace your
thermometer frequently; the average lifespan seems to be about a year.
We also found quite a few complaints about inaccurate
readings. While some of those are no doubt due to poor construction, it's clear
that many users aren't aware that a normal body temperature, taken orally,
isn't strictly 98.6 degrees. It can vary between 97 and 99 degrees, and
different temperature sites on the same person will yield slightly different readings.
Types of Digital Thermometers
Oral thermometers are easy to use, familiar to most people, and accurate as long as you can hold still with the thermometer under your tongue until it generates an accurate reading -- sometimes 30 seconds or more. Most oral thermometers can also be used for taking axillary/underarm readings and rectal readings. Eating and drinking can alter the results of an oral temperature, so wait at least 15 minutes after meals or drinks to take your temperature.
Ear (Tympanic) Thermometers
Ear thermometers use an infrared ray to measure the temperature inside your ear canal. They're a great choice for young children, six months or older, who haven't mastered holding an oral thermometer under their tongue or won't sit still for long. Also, your ear temperature won't be affected by variables such as eating, drinking, or mouth breathing, although laying with your ear on a pillow, having lots of ear wax, or using a hearing aid can all affect the readings.
Although many parents are uncomfortable with the idea of using a rectal thermometer, they are still the gold standard in temperature measurement for infants and small children under three years of age. Although some stick thermometers can be used for rectal measurements, purpose-built rectal thermometers have a short, flexible probe for comfort and a bulb-shaped handle that keeps you from accidentally inserting the probe too far.
Temporal (Forehead) Thermometers
When used correctly, temporal artery or forehead thermometers can be just as accurate as oral and rectal thermometers -- and they're far less invasive. They use an infrared ray to measure the temperature of an artery in your forehead and offer very quick readings, usually in 10 seconds or less. The downside is that most temporal thermometers come with a little bit of a learning curve, and if you don't get the ray targeted correctly, you won't get accurate results.
Finding The Best Digital Thermometers
"The Best Baby Thermometer"
"The Best Thermometer for Kids and Adults"
several summaries of expert, hands-on testing at ConsumerReports.org,
Parenting.com, TheSweetHome.com and TheNightLight.com. That said, user reviews
from retail sites like Amazon.com, Walmart.com and Target.com were just as
important for learning how each digital thermometer functioned in real-world
conditions, which included squirmy babies, fussy toddlers and sometimes
recalcitrant adults too.
thermometers aren't the only home health tools that must be accurate, reliable
and easy to use. We've also weighted heavily for real-world performance in our
reports on blood glucose monitors and blood pressure monitors.
It's hard to find fault with the simple,
versatile design of an inexpensive basic digital thermometer. A good, basic
digital thermometer can give years of accurate, reliable readings at very
With that in mind, our best-reviewed digital
thermometer is the (Est. $15). Although some users miss having a backlight on this
thermometer, they love its quick, accurate readings (usually in 15 seconds or
less, compared to 60 seconds for some of the competition) and appreciate the
fully waterproof housing that lets you wash the entire thermometer if need be.
This Generation Guard thermometer takes a
single LR41 battery and can be used for oral, underarm and rectal readings,
although it's best suited to oral readings. Underarm readings can be affected
by skin temperature and, although the Generation Guard's soft, flexible tip and
washability make it ideal for rectal readings, it lacks the broad base that eliminates
the risk of accidentally inserting it too far.
The Generation Guard thermometer is accurate to
0.2 Fahrenheit or 0.1 Celsius and it's easy to switch between Fahrenheit and
Celsius by holding down the power button. Its features are simple but useful --
it'll beep quietly (some say too quietly) to tell you when a reading is
complete, then display the last reading taken when you turn it on.
Finally, this Generation Guard thermometer is
subject to a "no questions asked" 30-day money back guarantee, and
their customer service department has developed an excellent reputation
for proactively doing everything
they can to ensure customer happiness. That's especially important for a
product that, like all inexpensive stick thermometers, tends to draw a lot of
user concerns about its accuracy and for sometimes arriving with dead or
"almost dead" batteries.
If all you want is a basic thermometer for
occasional use or as a backup to your usual thermometer, consider the Vicks Comfort Flex Digital (Est. $10).
Users generally love this thermometer's features, which include a fully
waterproof casing, recall of the last temperature taken, and a large, backlit
display that changes color according to the temperature reading. The same
features garnered the Vicks V966 Comfort Flex a "best thermometer for kids
and adults" pick from TheSweethome.com.
The Vicks Comfort Flex is also fast --
returning results in about eight seconds. However, it only received
"fair" ratings for its accuracy and repeatability in one test from a
major consumer advocate organization, and it draws enough user concerns about
dead batteries and accuracy that we can't award it Best Reviewed status
(although, to be fair, all digital thermometers receive a lot of those types of
complaints). It is, however, a good bargain if you're looking for a simple
thermometer for occasional use, and you can replace the 3V, CR1225 battery
Although simple and functional digital
thermometers are more accurate and widely available than ever, a few
manufacturers are heading in the opposite direction, creating digital
thermometers that sync with your smartphone to enable advanced functions.
The best of these, the (Est. $20) thermometer, is priced to be competitive with
higher-end basic thermometers. It plugs into your mobile device's earphone jack
-- with or without an optional extension cord -- and harnesses your
smartphone's power to do most of the processing.
The result is a light, durable device that can
be used orally, under the arm or rectally, and returns results in about 10
seconds. Users are very happy with the Kinsa Smart Stick thermometer's
accuracy, but it's the companion app that they really love. The free app lets
you track symptoms, chart temperature readings over time, and note medications
taken. You can even add photos to track conditions like a rash or sore throat.
The biggest hit of all, though, is the "bubble game" that helps keep
small children entertained and quiet as you take their temperature. They can
count or pop the bubbles that appear on the screen.
The Kinsa app also lets you store tracking
information for multiple people or submit your data anonymously to help
crowdsource information about illnesses circulating in your area. All of the
above are roundly praised by user reviewers, and Kinsa's proactive, helpful
customer service department gets lots of kudos too. The only major complaint we
saw is that users sometimes struggle to get the thermometer synced to their
phone, although we also noted the usual complaints we see about all digital
thermometers, mostly durability issues and questions as to temperature
There are, however, two catches to be aware of.
One, the Kinsa Smart Stick has no display of its own, so you can only use it in
conjunction with a smartphone that has the matching app. Two, along with the
user concerns about accuracy that seem to accompany all digital stick
thermometers, many note that this thermometer isn't compatible with every
device, so check the manufacturer's compatibility list before you buy. In particular, if you own an iPhone 7 or
7 Plus -- neither of which has a headphone jack -- you're out of luck until
Kinsa finds a way to make their Smart Stick thermometer work with Apple's