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Health Information | 03/10/2021

Choosing a Pediatric Thermometer

By  Dr. Emily Holden
Kids and fevers are pretty much inevitable. When your child spikes a fever, it can be pretty scary, especially if you’re a new parent. The reality is that fevers are common in children and usually pass within a couple of days. With that said, as we continue with cold and flu season amid the COVID-19 pandemic, monitoring the health of your children is very important. If your child seems warm, under the weather, or unusually fussy, it’s a good idea to check their temperature.

While many fevers often resolve on their own in children over six months, a fever can also be one of the first signs of serious illnesses like COVID-19. Therefore, it’s essential to use a thermometer to check your child’s exact body temperature and catch a fever early.

However, choosing which thermometer to use on your child can be confusing, especially when several models are marketed towards use for children. For this reason, you should follow the guidelines recommended by your child’s physician.

Types of Thermometers

There are several types of pediatric thermometers, with some better suited for younger or older children depending on their needs. Proper thermometer choice and usage ensure that your reading will be accurate, so you should familiarize yourself with each type as your child ages. The most common types of thermometers include:

  • Digital thermometers: Digital thermometers are held on or in a child’s body and use electric heat sensors to record the body’s temperature. These devices can be used in the mouth, armpit, or rectum.
  • Digital ear thermometers: Digital ear thermometers are held in a child’s ear. They use an infrared scanner to measure the temperature of the ear canal.
  • Temporal artery thermometer: Temporal artery thermometers use an infrared scanner to measure the temperature of the temporal artery in the forehead.
Mercury-based thermometers are no longer recommended for use on children, as they are considered dangerous. If a mercury thermometer breaks, your child may inhale the toxic vapor that can make them seriously ill. 

How to Use

Digital thermometers

Digital thermometers can be used in multiple ways. When choosing how to take your child’s temperature using a digital thermometer, you should consider your child’s age and medical conditions.

Rectal temperature: the most accurate reading, particularly for infants, ideal for the first 1-2 years of age. Before use, clean the end of the thermometer with warm water and soap or rubbing alcohol and apply a small amount of lubricant such as petroleum jelly. Place your child on their back with legs pulled up to the chest. Place just the very end of the thermometer into the rectum, about ½ inch deep. You should meet no resistance but if so, stop advancing. Sanitize after each use.

Axillary temperature: an alternative way to check the temperature at any age may be less accurate and underestimate a fever. For the best reading, you should ensure that the sensor touches the skin directly, without a layer of clothing in between

Oral temperature: By ages four to five, most children can tolerate a digital thermometer placed under the tongue. This is an accurate way to check the temperature in older children if done correctly. When taking a child’s temperature by mouth, you should sanitize the thermometer before and after use. It is also important to wait 15 minutes after the child eats or drinks before taking their temperature, as warm or cold food items may alter mouth temperature. When administering a digital thermometer by mouth, place the small end under the tongue towards the back of the mouth.

Digital ear thermometers

When taking a tympanic (ear) temperature, be sure to insert the sensor at the correct angle in the child’s ear and keep it at a proper distance within the ear canal, or the reading may not be accurate. Additionally, wax or ear canal shape may interfere with the reading. For this reason, parents should use ear thermometers cautiously if their toddlers do not often sit still. Additionally, this thermometer should not be used if your child has recently been in the water, as any water in the ear may impact the sensor’s ability to provide an accurate read.

Temporal artery thermometers

Temporal artery thermometers at home are an easy, fast way to check the temperature at any age but may not be as reliable as a rectal temperature, particularly for infants. Touchless temporal artery thermometers should be held directly in front of the forehead, about one inch from the skin. After a few seconds, the thermometer should display a clear temperature on the screen. Alternatively, temporal artery thermometers that make contact with the body should be placed on the center of the forehead and slowly moved towards both ears. After swiping the thermometer across the forehead, results should appear within seconds.

Reading the results

Once you have taken your child’s temperature, the results will appear on the device. It’s important to note that the normal temperature range varies depending on where you took your child’s temperature. Generally, a child is considered to have a fever if their temperature is above 100.4F.

When to contact your child’s doctor

Because external factors such as heat and exercise can cause a temporary increase in body temperature, you should check your child’s temperature multiple times before determining whether they have a fever. If two or more temperature readings have come back above the normal range, you should contact your child’s healthcare provider.

While a fever in children may not always be cause for concern and may actually be a sign that your child is successfully fighting an infection, fever is a common symptom of COVID-19 as well as the flu. For this reason, every fever should be taken seriously and closely monitored. Your Atrius Health provider can help determine whether additional screening or testing is necessary to rule out serious illness and help your child recover.

About The Author

Dr. Emily Holden

Dr. Emily Holden joined Atrius Health in 2020 and is a pediatrician at our Harvard Vanguard Peabody location. She received her medical degree from Tufts University School of Medicine. Dr. Holden completed both her internship and residency at Tufts Floating Hospital for Children.

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