Thermometer buying guide

A digital stick thermometer is the most widely sold and cheapest type. Look for one with an LCD display that's easy to read and a start button that's easy to press. Digital thermometers rely on batteries to work.

Decide whether you want a rigid tip thermometer, such as Wal-Mart's Relion Rigid 60 Second shown here but not included in our Ratings, (about $3) or a flexible-tip thermometer, such as the one Mabis, (about $17). Generally, children and adults who had their temperatures taken orally in our tests said that rigid digital stick thermometers were less comfortable than flexible types.

Many rigid-tip thermometers can be used to take underarm or rectal temperatures as well as oral temperatures. But not all flexible-tip thermometers can be used rectally, so you'll need to read the labels.

This type of oral digital thermometer, such as the Lumiscope Babytherm Pacifier Thermometer shown here (about $7) looks like a pacifier, and it displays a reading after your baby sucks on it for 90 seconds or longer. We didn't test this type of thermometer. But oral thermometer readings tend to be as much as 1 degree F lower than rectal thermometers, and aren't considered as accurate for children under 3.

Infrared thermometers measure heat being emitted by the body. Some infrareds can be difficult to position, but their digital readout takes just 1 to 3 seconds--among the shortest times of all thermometers tested. But these thermometers are also among the most expensive available--and they aren't necessarily more accurate than less-costly digital stick thermometers.

Devices such as the Braun ThermoScan Ear Thermometer shown here (about $50) measure the tympanic temperature--the temperature inside the ear canal. This type of thermometer is quick and easy to use.

The top infrared thermometers in our tests were forehead models such as the Vicks V977 (about $37), which has a large backlit display and colors that indicate a normal temperature, mild fever, and high fever.

Not surprisingly, the children in our study preferred forehead-type thermometers to oral and ear types. One young participant expressed a common sentiment among testers of forehead thermometers: "It felt really smooth on my forehead and it glided easily."

This is the first time we've tested a non-contact infrared thermometer, the Thermofocus BV-1500, which at $80 was the most expensive thermometer tested. It works by holding the thermometer wand an inch or two from your sleeping child's forehead and pressing the button showing two red circles of light on the forehead. Then you move the thermometer closer to or farther from the forehead until the two red circles converge into one red circle and release the button, at which point the temperature is displayed. If your child is restless, it may be difficult to get an accurate temperature. The manufacturer says you can also use this thermometer to measure the temperature of a room or the baby's bath or bottle, but those features were not tested.

A large, backlit display like the one found on the Vicks V977 and large digits can help you to easily read temperatures at night or in low light.

A line or mark showing an end point for insertion can prevent injury to your baby when you're taking a rectal temperature. Be sure to follow the manufacturer's instructions carefully when using thermometers rectally. Thermometers were not tested rectally.

An audible beep or other signal indicating that the reading is complete means you won't have to keep checking your watch. The Exergen Temporal Scanner, (about $50) has this feature as do most of the thermometers we tested.

Some models will beep when a temperature exceeds 99.5 degrees F. Others have visual fever alerts, with the display changing color (green, yellow, red) to indicate temperature level. These features were not tested. The CVS Flexible Tip Digital is among the thermometers we tested that have audible fever alert.

Some models record the last temperature taken, so you can determine in which direction your baby's fever is going. Some also feature an automatic shutoff to preserve battery life. We didn't test these features.

Some thermometer buttons will respond to your touch with a sensation or a beep, so you'll know when the device has been turned on. The Braun Thermoscan ear thermometer and Exergen temporal scanner are two models with this feature.

As simple as digital thermometers are, some have bells and whistles that you might find convenient, such as soft or curved tips, or beeps that tell you when they're in the right spot or when they've finished measuring the temperature.

A readout from a digital stick thermometer may take 10 seconds to more than 80 seconds, depending on the model. Infrared thermometer readouts take just 1 to 3 seconds, but may not be any more accurate than an inexpensive digital stick thermometer. So the infrareds may not be worth their cost--unless you have a child who simply won't stand for using the others.

Be aware that probe covers and protective case covers may pose a choking hazard, so thermometers and their accessories should be kept out of the hands of unsupervised children.

If you're purchasing an inexpensive digital stick thermometer to take a rectal temperature, consider purchasing a second one to take oral temperatures so you won't have worry about keeping disposable thermometer covers on hand. Label each one with permanent marker for its particular use.