Why It Is Important to Take Your Child's Temperature

It can be stressful when your child has a fever.

Yet it’s important to remember that fever itself typically causes no harm and goes away within 72 hours. Fever is a sign of the immune system doing what it was designed to do: Help the body rid itself of illnesses, such as colds or other viral infections.

But what temperature is cause for concern? And what actions should you take before reaching out for medical assistance or advice?

Here’s what you should know to help you decide.

What Is a Healthy Child’s Temperature?

A healthy body temperature varies from child to child and may even vary throughout the day. Normal temperatures range from 97° to 100.4° Fahrenheit (F) (or 36.1° to 38° Celsius). Anything above 100.4° F (when measured orally with a thermometer) is considered a fever in both children and adults.

However, it is important to note that the actual number is less important than other associated symptoms or your child’s actions. Your child’s age and ability to communicate how they feel also plays a role in making a determination of next steps.

Because fever can be associated with illnesses such as pneumonia, urinary tract infections, ear infections, meningitis, and other serious infections, it’s important to pay close attention when children are not acting like themselves and to take their temperature. Also take into consideration how long they have not been acting like themselves before making any decisions.

Other causes of fever in children include:

  • Overheating from being overdressed.
  • Spending too much time in the sun.
  • Reaction to a vaccination.

Your child may have a fever if they exhibit any of these symptoms:

  • Crankier or fussier than usual.
  • Sweaty, clammy, or flushed cheeks.
  • Hot to the touch on forehead, back, or stomach.
  • Lack of interest in play or less active.
  • Poor sleeping.
  • Poor eating or nursing.
  • Convulsion or seizures.

If you think your child has a fever, it’s important to use a thermometer to take an accurate temperature. Assessing your child’s temperature through touch is not an accurate reflection of their internal body temperature. The thermometer reading will help you decide if you need to take further action.

What Is the Best Type of Thermometer to Use?

There are a variety of thermometers available today, so it can be hard to know what is best to use with your child. It’s important to follow age recommendations and specific instructions for the thermometer that you use.

When shopping for a thermometer, we recommend searching for:

  • Digital thermometers: These use electronic heat sensors to record body temperature. They are easy to use orally, rectally, or axillary, and provide accurate readings in about one minute or less.
  • Digital temporal or noncontact infrared thermometers: These thermometers use an infrared scanner to measure the temperature of the temporal artery in the forehead. They provide quick readings within only a few seconds and are one of the least invasive options. These thermometers have only become popular within the last few years, but early research has shown that they may be as accurate as rectal thermometers in children. Note that forehead temperature readings run around 1°F cooler than oral temperature readings, so you should add 1°F to your reading for the most accurate measure.

The following thermometers are less accurate and, thus, less recommended than the ones above. However, they could be used for a general gauge of fever where an exact measurement is less critical:

  • Ear (tympanic) thermometers: These use an infrared scanner to measure the temperature inside the ear canal and give quick results. However, if an ear thermometer is not properly inserted — which is more likely to happen with babies because of their small ear canals — they can give inaccurate readings. These thermometers also tend to be more expensive.
  • Pacifier thermometers: These relatively new thermometers mimic your baby’s soothing device. The issue is that they do not offer a reliably accurate reading in the way that a rectally administered digital thermometer can. Studies have found that pacifier temperature readings run around one-half of 1°F cooler than oral temperature readings, so you should add one-half of 1°F to your reading for the most accurate measure.

We do not recommend using the following types of thermometers:

  • Glass thermometers: These contain mercury which, if broken, would release pieces of glass and highly poisonous mercury. They should never be used and haven’t been available in stores since 2001. If you or your baby are exposed to mercury, seek medical advice immediately. If you still have a glass thermometer containing mercury in your home, visit Earth911.com to locate your local household hazardous waste facility or events where you can properly dispose of and recycle items containing mercury.
  • Strip-type temporal thermometers: These are strips that are held against the forehead and show the temperature of the skin, rather than the body. For that reason, they are not considered an accurate way of taking a temperature.

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Tips for Taking an Accurate Temperature by Technique

The best technique for taking your child’s temperature will depend on their age and temperament. It is most important that the measurement is accurate. Below are some tips for taking your child’s temperature via different techniques.

By Rectum

To take a rectal temperature, first sanitize the thermometer. Wash it with soap and water or wipe it down with rubbing alcohol. Lay your baby on their belly or back with their legs bent toward their chest. Apply a small amount of petroleum jelly to the tip of the thermometer bulb and gently insert it into the rectal opening. This should not cause your baby any pain. They may fuss about positioning or holding still, but taking their temperature rectally should not cause your baby distress.

Hold the thermometer in place for about 2 minutes until you hear a beep. Then gently remove the thermometer and read the temperature. Sanitize the thermometer again before storing.

By Armpit

To take an axillary temperature, hold your baby comfortably on your knee or sit your child down and and put the thermometer into the skin of their armpit. Gently hold their arm against their body to keep the thermometer in place until you hear the beep that the reading is ready. The display screen will show your child’s temperature. This is an easy and reliable way to get an accurate reading.

By Forehead

As mentioned above, strip-type thermometers that are applied to the forehead do not provide accurate readings for the body. They should not be used when you’re trying to determine if your child has a fever. However, digital temporal or noncontact infrared thermometers that measure temperature via the forehead provide quick and accurate readings.

To ensure that you are getting the most accurate reading regardless of the method used, consider environmental conditions. If your child is bundled in many layers of clothing or wrapped tightly in a blanket, this could also affect the reading.

When Should I Seek Medical Care Regarding My Child’s Fever?

If your child is under 2 months old and has a fever, contact your pediatrician right away. For older children, your child may be able to recover from home, but seek medical care if the fever persists or worsens or if you have questions.

These tips may help if your baby’s temperature keeps going up:

  • Dress your child in a comfortable amount of clothing based on their state. Be sure not to overdress them. If they are acting cold or have the chills, add a layer or layers. If they are warm or sweating, remove a layer or layers.
  • Give your child enough fluids. Whether breast milk, formula, electrolytes, or water (depending on your child’s age), it’s important to avoid dehydration. A dehydrated baby may have fewer wet diapers, a dry mouth, or no tears when crying.

Do not give a child under 6 months old any medicine containing ibuprofen. Be sure to talk with your pediatrician about dosage and read all instructions before administering fever-reducing medicine to your baby.

If your child is older than 6 months and your pediatrician approves it, you can give your baby either children’s acetaminophen or children’s ibuprofen. Never give your child aspirin because of the risk of Reye’s syndrome.

If you are ever concerned about your child’s temperature, call your pediatrician first.

What To Do If Your Child’s Temperature Is Fluctuating

Our body temperatures regularly fluctuate throughout the day, and a healthy temperature range varies by a few degrees. It is normal for your child’s temperature to go up and down every few hours. It’s important to monitor their symptoms and behavior to determine the next course of action.

Seek immediate medical assistance if:

  • Your child has other signs of an illness along with their fever, such as a rash, dehydration, or weakness.
  • Your child is under 3 months old and their temperature is above 100.4° F.
  • Your child is older than 3 months old and their temperature is above 102.2° F.

When communicating your child’s fever to a medical provider, it is always helpful to convey the method you used to take the temperature. This helps the provider assess the accuracy of the reading.

While it can be concerning at first if your child is showing symptoms of a high temperature, there are steps you can take to ensure they are safe.

For more information about taking your child’s temperature, contact your pediatrician or UPMC Children’s Hospital of Pittsburgh.

About Pediatrics

From nutrition to illnesses, from athletics to school, children will face many challenges growing up. Parents often will make important health care decisions for them. We hope to help guide both of you in that journey. UPMC Children’s Hospital of Pittsburgh is a national leader in pediatric care, ranking consistently on U.S. News & World Report’s Best Children’s Hospitals Honor Roll. We provide expert treatment for pediatric diseases, along well-child visits, urgent care, and more. With locations across Pennsylvania, Maryland, and West Virginia, you can find world-class care close to home. We also work closely with UPMC Magee-Womens Hospital, a national leader in care for newborns and their mothers. Our goal is to provide the best care for your children, from birth to adulthood and beyond. Visit our website to find a doctor near you.