Although some pediatricians have moved away from recommending rectal thermometer readings, most still depend on this as the most accurate way of determining whether your child has a temperature, especially if he or she is under three years old. Odds are very good that if you call in to your medical provider's after-hours care line -- which happens more often than you may anticipate -- you'll be asked to provide rectal temperature readings to the doctor or nurse on call.
Many parents are uncomfortable with the prospect of taking rectal temperatures with a basic digital stick thermometer, because it can be hard to tell if you've inserted the probe far enough (or too far), and the rigid probe on most stick thermometers can be uncomfortable.
Our Best Reviewed rectal thermometer, the Vicks V934 (Est. $30) baby thermometer, solves those problems by having a short, flexible probe in a bulb-like base. It's one of the top picks from Melanie Rosen at TheNightLight.com, thanks to its straightforward, fast operation and its relative comfort.
Users agree that the Vicks V934 lives up to the manufacturer's promise on its website: "You might be a little uncomfortable, but your baby won't be." Most say that baby hardly even notices this Vicks thermometer, and many owners love theirs so much that they give them out to other expectant mothers as baby shower gifts.
This little rectal thermometer draws lots of user praise for having all the right features to make things easy on baby and you: The bulb-shaped grip fits easily in your hand and keeps you from inserting the tip too far, the large, backlit display returns readings in about 10 seconds, and it stores the last reading taken in internal memory. Once baby gets older and starts to object to rectal temperatures, you have the option of using the V934 to take underarm (axillary) readings instead.
Although the body casing of the Vicks V934 isn't fully waterproof, the hypoallergenic tip is, so it's easy to clean with soap and water or rubbing alcohol. It takes a single SR41/LR41 battery that should last for about 200 hours of use, and is accurate to 0.2 degrees. Users are especially complimentary of the Vicks V934's consistency, with many saying they switched to it after getting frustrated by inaccurate readings from other thermometers. Although we didn't see any notable comments about problems with this thermometer -- in fact, it usually lasts for years -- it is backed by a lifetime warranty.
If cost is an issue or you need a thermometer quickly and the Vicks V934 is not available in your area, our runner-up is the Safety 1st Gentle Read rectal thermometer (Est. $9) Although it's not quite as popular with users as the Vicks V934 baby rectal thermometer, the Safety 1st Gentle Read still gets lots of love for its fast (8-second) readings, its short and flexible tip, and the wide body that keeps you from accidentally inserting it too far.
The Safety 1st has a similar range of display features as what you'll find on the Vicks V934: A large, easy to read readout, a beep signal once it's done, and a memory function that stores the last reading taken. It uses a single LR41 button cell battery.
The Safety 1st is also a top pick from the editors of TheNightlight.com, who tested 13 different thermometers, and it also gets a nod from Juliet Spurrier, MD, "mom-in-chief" of BabyGearLab.com. However, we do note a number of user complaints about thermometers arriving with dead batteries, so don't wait until baby has a fever before you check to make sure the thermometer works. Take several readings while baby is feeling well and pay attention to the consistency: Although feedback for this thermometer's accuracy is mostly positive, it does draw some mixed reviews that seem to be related either to quality control or insertion technique.
Once baby is too old for a rectal thermometer, consider upgrading to a thermometer that takes his or her temperature from the ear. Doctors often use an ear thermometers because your eardrum shares blood supply with your hypothalamus -- the body's temperature control center -- and so reflects changes in core temperature quite quickly. Also, unlike oral temperature readings, your ear temperature won't be affected by variables such as eating, drinking, or mouth breathing, although laying with your ear on a pillow or using a hearing aid can affect the readings.
Digital ear thermometers have a little bit more of a learning curve than some other types, with some owners saying they struggled to learn proper technique. One of the most common mistakes is not inserting the thermometer far enough, so it measures the temperature at the side of the ear canal (wrong target) instead of the eardrum (correct target). Once you've nailed the technique, though, ear thermometers can return quick, easy readings with a minimum of fuss, especially if they have a soft, "pre-warmed" tip like our top pick, the Braun Thermoscan 5 (Est. $40) ear thermometer.
The soft, warm tip on the Thermoscan 5 eliminates both the discomfort and the inaccurate readings that can sometimes result from using an ear thermometer with a cool tip, and its short enough that parents say they don't worry about hurting their child's eardrum. A light-and-beep system helps you guide the thermometer into the proper position. It won't take a reading until you get it positioned correctly -- a process that sometimes frustrates users, but ultimately saves them from inaccurate readings.
Results only take a couple of seconds to pop up on the screen, with color-coded background lights that illuminate green, yellow or red to signal normal, elevated or high temperatures. Users are very complimentary about the Braun Thermoscan 5's accuracy too, saying it often returns multiple readings within about .2 degrees of each other. They also love that it uses easy-to-find AA batteries, and say it works just as well for cranky or fidgety adults as for kids.
Feedback on the Thermoscan 5's consistency and durability is almost universally positive. However, don't forget to factor in the cost of Disposable Lens Filters (Est. $6 per 40), both for hygiene considerations and because the Thermoscan 5 won't operate without them.
For another excellent ear thermometer that doesn't use probe covers (it has an easy-to-clean probe surface instead), consider the Kinsa Smart Ear Thermometer (Est. $50). It doesn't draw as many reviews as the Thermoscan 5, but those who have tried it say the Kinsa returns accurate readings in just a second or two. One-button operation and an illuminated display that changes color, much like the Braun Thermoscan's, make it easy for sleep-deprived parents to feel confident in their readings.
Many parents also love the Kinsa Smart Ear Thermometer for its "neato" factor; the companion app gives it the same capability as the Kinsa Smart Thermometer (Est. $18) discussed in the previous section, letting you track temperatures, symptoms and medications, and even add photos to your records.