Fever in Babies and Newborns

From time to time, your little one will have a raised temperature and may be sick. Obviously, this isn’t fun for your baby, and it also may be stressful for you as a parent, especially if you’re not sure what might be causing the fever.

Keep reading to find out what symptoms to look out for, what temperature is considered to be normal and a high fever in babies, and what you can do to try to bring down your little one’s temperature and keep her comfortable.

What Is a Fever?

A fever is not an illness in and of itself; rather it’s a symptom of an underlying illness, typically an infection.

This temporary rise in temperature is the body’s way of fighting bacterial or viral infections, stimulating the white blood cells that battle the infection.

Fever can occur with any type of infection, whether it’s a common childhood illness such as an ear infection, a cold, sore throat, croup, or something more serious such as influenza and pneumonia (respiratory infections) or meningitis (a brain and spinal cord infection). This is why part of treating a fever will always involve treating the root cause of it, too.

It may be difficult to tell if your baby has a fever. But if your baby looks or behaves in a way that's out of the ordinary, and you think your baby may have a fever, it's a good idea to take her temperature.

A change in behaviour or activity level is often a better indicator of illness than how high the fever is. For example, a newborn who's sick might be fussier than usual, or sleeping more than usual. These symptoms in your newborn, paired with a fever, indicate that she is most likely ill.

What Temperature Is Considered a Fever for a Newborn or Baby?

Although it’s normal for your baby’s temperature to vary a little throughout the day, a thermometer reading of 38 degrees Celsius or higher is usually an indication of a fever.

Here’s a breakdown of the temperature that is considered a fever or even a high fever depending on your baby’s age:

What Is Considered a Fever in a Newborn?

If your newborn is 2 months or younger and has a temperature of 38 degrees Celsius or higher, this is a sign of fever. You must contact your healthcare provider immediately so that she can check to make sure there is not a serious underlying infection or disease.

What Is Considered a High Fever in Babies?

It’s considered to be a high fever if your baby is between 3 and 6 months and has a fever of 38.3 degrees Celsius or higher, as well if your baby is older than 6 months and has a fever of 39.4 degrees Celsius or higher. If your baby has a high fever, tell your provider right away.

How to Take Your Baby’s Temperature

If you suspect your baby has a fever, it’s best to use a digital thermometer to take her temperature. Simply placing your hand on her forehead is not a good way to gauge a fever.

Follow the instructions on the thermometer packaging, as each product can work a bit differently, or ask your healthcare provider to show you how to take your little one’s temperature.

If you take a reading from the rectum, ear, or forehead, a reading of 38 degrees Celsius or higher indicates a fever. For infants 2 months or younger, rectal readings are considered the most accurate.

For a reading taken from the armpit, 37.2 degrees Celsius or higher is considered a fever. The cutoff temperature is lower because armpit measurements are less accurate. Of course, if this is the only way you can get a reading, it can at least give you some indication of your little one’s temperature.

How to Bring Down Your Baby’s Fever

Here’s how you can treat your baby’s fever:

• Cool the environment. Make sure your baby’s room is cool and comfortable. Consider setting up a fan to circulate cool air throughout the room.

• Use lighter clothes. Dress her in lightweight clothing. You want to encourage body heat to escape so that her temperature drops.

• Give lots of fluids. Make sure your baby is getting plenty of fluids.

• Provide medicine. Your healthcare provider may recommend a fever-reducing medicine. We cover this in detail in the next section.

If the fever is a result of a contagious condition such as the flu or chicken pox, it’s best to keep your baby away from other children, older people, and anyone with a weaker immune system.

Fever-Reducing Medications

A fever may not require medication unless your baby is uncomfortable. Ask your healthcare provider whether fever-reducing medicine is needed or not and carefully follow any dosage instructions.

Although you might have some over-the-counter fever-reducing medications stocked in your own medicine cabinet, these are not always suitable for babies or young children. You should give your baby only what your healthcare provider recommends as safe, typically acetaminophen or ibuprofen in an appropriate dose.

Aspirin is not recommended for children as it may lead to a serious condition called Reye’s syndrome, and you should give acetaminophen or ibuprofen to your little one only after you’ve gotten the green light from your provider. This is because some of these medications shouldn’t be given if your child has certain conditions.

There are also age restrictions. For example, acetaminophen should only be given once your little one is 3 months old, and ibuprofen only once your baby is 6 months old.

If your baby is younger than 2 months, always consult with your provider before giving any medication.

When it comes to dosage, follow the instructions on the product labeling. Dosage is typically based on your baby’s age or weight. Always use the measuring device that comes with the product rather than a household teaspoon.

When to Call Your Healthcare Provider

As mentioned above, call your baby's healthcare provider

• when your baby who is 2 months old or younger has a temperature of 38 degrees Celsius or higher (call immediately)

• when your baby who is 3 to 6 months old has a temperature of 38.3 degrees Celsius or higher

• when your baby who is older than 6 months has a temperature of 39.4 degrees Celsius or higher.

You'll also want to contact your provider if your baby’s fever lasts for more than 24 hours, or if your newborn or baby has any combination of these symptoms in addition to a fever:

• Vomiting

• Diarrhea

• Uncontrollable crying

• Fussiness

• Sluggishness

• Blue lips, tongue, or nails

• A bulging or sunken spot anywhere on the head

• A stiff neck

• Limpness

• Trouble breathing

• Drooling

• Seizure (see more on febrile convulsions below)

Febrile Convulsions

Rarely, a fever can trigger what is called a febrile convulsion—a seizure that can happen in children between 6 months and 5 years. This type of seizure usually lasts for a few seconds or up to one minute.

Witnessing your child having a febrile convulsion might be one of the scariest things you can imagine, but rest assured that this type of seizure is usually harmless.

These are the signs of a febrile convulsion:

• Your child looks unusual, stiffens, twitches, and rolls his eyes

• He’s unresponsive or passes out

• He vomits or urinates during the seizure

• His skin looks darker than usual.

If your baby is having a febrile convulsion, take the following steps:

• Lay him on the bed or floor, away from any objects that could hurt him

• Turn him on his side to prevent choking

• Loosen the clothing around his neck and head

• Watch for any trouble breathing, such as his face turning blue; call 911 immediately for any breathing problems

• If the seizure lasts more than 15 minutes, call 911 immediately.

Don’t

• put anything in your baby's mouth

• hold or restrain him

• administer fever-reducing medication

• place him in a cool or lukewarm bath.

If your baby has had a febrile convulsion, let your healthcare provider know as soon as you can so you can schedule a checkup.

Conditions That May Be Mistaken for a Fever

Teething may contribute to a small rise in your baby’s temperature but it’s not usually the cause of a fever. (Learn more about the symptoms of teething and about 'teething fever')

Heatstroke is often confused with fever, too. Be aware that your baby’s body heat can rise to dangerous levels if he is overdressed or is in a hot environment such as a hot beach or an overheated car. If you think your child might have heatstroke, take him to the emergency room.

It’s natural to be uneasy when your baby has a fever, but with time and proper home care, your baby’s fever should soon subside. Always feel free to reach out to your healthcare provider with any questions or concerns. Before long, your little one will be back to his happy self.