How to Choose a Good Child Thermometer and When to Call the Doctor

How to Choose a Good Child Thermometer and When to Call the Doctor

Written by Jennifer Lai, M.D. on Aug 29, 2015, 9:00:00 AM

If you’re standing in an aisle at a drugstore looking at thermometers because your child is sick, chances are you already have a lot on your mind. Trying to pick out something like a thermometer can be overwhelming in an already-stressful situation. Basically, there are three types of common thermometers: the digital multiuse thermometer, the temporal artery thermometer and the tympanic thermometer. Before you head to the store, it’s important to know how to use each kind, what they’re good for, and when to worry about your child’s temperature.

The Digital Multiuse Thermometer


A digital multiuse thermometer is probably the thermometer you’re most used to seeing, and to be honest, it is the thermometer I would recommend above the other two on this list. In the long run, digital multiuse thermometers tend to work better in the long run.  

These instruments read temperature via the sensor located at the tip of the thermometer when touching a part of the body. These may be used orally by placing the sensor under the tongue, rectally or axillary by placing the sensor under the child’s armpit.

For oral use, your child should be at least 4 years old. Rectal temperature can be taken between birth and 3 years old and axillary temperature can be taken at any age. Keep in mind, though, that axillary temperature is the least reliable method to check temperature.

Temporal Artery Thermometers


Using temporal artery thermometers has become a popular method of temperature measurement at home because of their ease and non-intrusiveness. Most of these thermometers are used by placing the sensor on the middle of your child’s forehead and gently sweeping the sensor across their head towards their temple. Temporal artery thermometers work by reading the infrared heat waves released by the temporal artery, which runs across the forehead.  

This instrument originally was considered best used with children older than 3 months, but new research suggests this type of thermometer can be useful in helping to screen for temperature in children as early as newborn.

Tympanic Thermometer


This particular thermometer is one you’ve most likely seen at your physician’s office. It can be used at home, as well. Tympanic thermometers are inserted into the ear and read the infrared waves released by the ear drum.

This type of thermometer is not very invasive, but it’s also not generally considered as a reliable instrument for home use. Their benefits are limited because 1) they shouldn’t be used in babies younger than 6 months, 2) the placement of the instrument in the ear canal must be correct to get an accurate reading and 3) too much earwax can cause false readings.

When Should I Worry About Fever

First, remember that a child’s temperature often runs slightly higher than an adult’s. We consider it a fever if the thermometer reading is greater than 100.4 F. Here’s when you shouldn’t worry about your child’s fever:

  • If the fever is low grade, especially if the child has recently received immunizations.
  • If the temperature does not exceed 102.5 F and your child is between 3months and 3 years old, or if the temperature is up to 103 F and your child is older than 3.
  • If the fever has lasted less than five days and your child’s behavior is relatively normal. 

Having said that, there’s nothing wrong with checking with your pediatrician’s office or the Kelsey-Seybold Nurse Hotline if you have any doubts. On the other hand, call your doctor immediately if:

  • Your child is younger than 3 months and develops a fever.
  • Your child’s fever is higher than 104 F.
  • Your child’s fever lasts longer than five days.

It’s always better to be safe than sorry. If you have any concerns about your child’s health, make a doctor’s appointment. The piece of mind you’ll have after your pediatrician sees them is well worth the doctor visit.


Dr. Jennifer Lai is a board-certified pediatrician at Kelsey-Seybold’s Spring Medical and Diagnostic Center. She’s accepting appointments for kids of all ages. Her clinical interests include general Pediatrics, newborns, autism, and obesity.



Topics: child thermometer, fever, temperature, when to worry about fever, digital thermometer, temporal artery thermometer, tympanic thermometec

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