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The right type of baby thermometer to keep in your first aid kit

A fever, especially in young children, can be frightening for parents. Knowing what symptoms cause fevers or how to measure your child’s fever can be difficult. Here are several guidelines for choosing the most accurate baby thermometer and the best thermometer for your first aid kit.

Please note that general advice is not a substitute for professional medical care and diagnoses. Seek professional medical help when your child develops a fever and other symptoms.

Normal temperature in young children

The normal temperature in young children is 98.6 degrees Fahrenheit (F) if you use an oral thermometer. A rectal temperature should be 99.6 degrees Fahrenheit. An oral temperature of 99.5 degrees or a rectal reading with the best baby rectal thermometer of 100.4 degrees or higher means there’s a fever.

child getting temperature taken

When to contact your health provider

Call your health care provider as soon as possible if your child is younger than 3 months and has a rectal temperature of 100.4 degrees Fahrenheit or higher. Contact your health care provider if your child is 3 to 6 months and has a temperature up to 102 degrees Fahrenheit with signs of being unusually irritable, lethargic, uncomfortable, or having insomnia. You should also call your health care provider if your child is age 6 to 24 months and has a temperature higher than 102 degrees Fahrenheit lasting longer than one day.

A child of any age who has fever and symptoms such as a cough or diarrhea should see their health care provider as soon as possible. You should contact your health care provider if your child of any age shows symptoms of difficulty breathing or swallowing, abdominal pain, inability to keep fluids down (such as with constant vomiting), rash, stiff neck, burning sensation during urinating or inability to urinate, or difficulty in waking. Also, be extra careful if your child is not up to date on immunizations. Call emergency services if your child has a seizure or is unresponsive.

Thermometer types

There are many thermometer types, and each is useful. Modern thermometers are primarily digital with an electronic readout for the temperature. However, matching the thermometer type to the correct age of your child is important. Some thermometer types are:


A rectal thermometer is one you place in your child’s rectum through the anus. Rectal thermometers are best for children up to 3 months old. One of the best baby rectal thermometers is the Fridababy® Quick-Read Rectal Thermometer because this thermometer is made of durable materials and features a short tip for a precise fit. The thermometer is water-resistant.


Oral thermometers are thermometers you place in a child’s mouth. Use oral thermometers in children 4 years and older. Like rectal and axillary thermometers, oral thermometers use heat sensors to take the temperature. Oral thermometers are less accurate than rectal thermometers but are less invasive and embarrassing for older children.


Ear thermometers measure temperature through the tympanic membrane using infrared scanners to measure the temperature inside ear canals. Earwax or a smaller, curved ear canal can interfere with its accuracy. Use these thermometers for children 4 years or older. The iProven DMT-489 Forehead and Ear Thermometer gives you a handy two-in-one tool.


From 3 months to 4 years, you can use a digital thermometer to take a temperature. An axillary thermometer is a thermometer you place under a child’s armpit to take a temperature. The axillary thermometer is not as accurate as a rectal or an oral thermometer in showing the correct temperature. A good oral and axillary thermometer is the SafetyFirst Rapid Read 3-in-1 Thermometer, featuring a flexible tip and accurate reading in eight seconds.

Temporal artery thermometers

Temporal artery thermometers use infrared scanners to measure temperature in the forehead. These thermometers are useful for children when they sleep or those who find it difficult to use rectal, oral, axillary, or ear thermometers. Temporal artery thermometers may not give you a temperature reading that is as accurate as taking a rectal or an oral temperature reading, depending on the thermometer brand. These thermometers use infrared scanners to measure temperatures of the temporal artery in the forehead. You can use this thermometer even while a child is asleep.  The Exergen Temporal Artery Thermometer gives a quick, easy reading.

Contactless thermometers

Contactless thermometers are thermometers used primarily in hospitals and businesses that need to scan employees for diseases. While professional contactless thermometers are accurate, those for home use aren’t as accurate as using a rectal thermometer.

What not to use

Don’t use digital pacifier thermometers or fever strips because these are not the most accurate baby thermometers.

Mercury warning

Avoid thermometers that have mercury. Health care professionals once used thermometers with methyl mercury because mercury expands with heat. A slight amount of mercury is situated in the base of the thermometer. Heat warms the thermometer base, and the mercury rises in the narrow thermometer tube. However, mercury thermometers contain the toxin mercury and are not as accurate as digital thermometers. Most healthcare professionals use and recommend digital thermometers. Some digital thermometers use expanding metal components instead of expanding mercury with digital technology for safe results. Others use electronic circuitry.

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