The Differences Between Baby Thermometers

Digital Thermometers

• Rectal temperatures, which measure core body temperature, remain the gold standard for accurate measurement, according to the American Academy of Pediatrics. Digital thermometers that use batteries have replaced the mercury models; they work quickly and provide accurate readings. To use a digital stick thermometer rectally, lay your baby across your lap, bottom up, or put him on his back and hold his legs up. Lubricating the tip makes insertion easier for everyone. Insert the tip about 1/2 to 1 inch into the rectum. You can also use digital stick thermometers under the armpit, but the readings aren't as accurate. If you find an old mercury thermometer, get rid of it, the American Academy of Pediatrics (AAP) advises. The mercury and the glass both pose hazards; glass can shatter and mercury is a toxin. Don't just throw it out; call your local health department and ask what to do with it.

Tympanic Thermometers

• Tympanic thermometers use infrared to measure your baby's temperature inside the ear. Tympanic thermometers read quickly, often within a few seconds, according to Consumer Reports. They can be difficult to position correctly, though, and children often fight them. Ear wax in the ear canal can also impact the reading. The AAP recommends against their use for babies under age six months. If you don't fit the tip into the ear canal properly, you can cause your baby pain and get an inaccurate reading. According to a "Journal Watch Pediatrics and Adolescent Medicine" study published in September 2010, tympanic thermometers give a reading closer to rectal thermometers than temporal thermometers in children.

Temporal Thermometers

• Temporal thermometers use infrared to measure the heat waves released by the temporal artery, which runs across the forehead. Temporal thermometers come in several different types; you press some against the temporal artery and sweep others across the forehead. Temporal readings were as accurate as axillary readings in preterm newborns in intensive care units in a study published in the February 2011 issue of "Advances in Neonatal Care."

Temperature Strips

• Strips that you attach to your baby's forehead sound like a wonderfully non-invasive method of temperature taking, but they have several drawbacks. They can take as long as two to three minutes to read -- a long time to stand there making sure it doesn't fall off your baby's forehead -- and they don't provide very accurate readings. However, they can work as a screening method in a pinch. They measure skin temperature, not core body temperature.

Pacifier Thermometers

• Pacifier thermometers measure oral temperature; while they seem like a good idea, your baby has to keep sucking until a reading registers, usually around 90 seconds, according to Consumer Reports. Oral readings are generally around 1 degree F lower than rectal temperatures, so adjust the reading accordingly when reporting it to your doctor.