Understanding And Managing Fever In Babies And Young Children

A baby with a fever can throw a lot of new and even experienced parents into a panic. While fever can be a sign that their immune system is fighting some type of infection, the elevated body temperature itself is seldom dangerous, and may help your infant kill the invading organism.
Fevers tend to occur more commonly in infants and young children. This is, in part, due to the fact that their rate of infection with common viruses is higher. Fevers can occur at any time of day or night, though temperatures tend to be higher at night in many viral infections.

What Causes Fevers In An Infant?

Infant fevers can have several different causes. First, there is the natural temperature variation. Infants have lower body temperatures when they first wake up, and higher normal temperatures later in the day. Metabolic processes such as eating and digesting can elevate the normal body temperature a few tenths of a degree. Teething can cause an elevated temperature, though it seldom exceeds 100 degrees.
Common causes of fever in infants include vaccine reactions, respiratory illnesses (i.e., colds, ear infections), other viral infections, systemic inflammatory disorders, and bacterial infections. Much of pediatric medicine is geared toward early identification and treatment of this last category.

Identifying A Fever In An Infant

An infant is considered to have a fever if their temperature is:

  • 100.4°F when taken rectally
  • 99°F or higher when taken by other methods
  • Children older than three months of age don’t require a doctor’s visit for a low-grade fever, but if you have any concerns, please contact your pediatrician.

How To Check Your Baby’s Temperature Correctly

There are a few different ways to check an infant’s temperature.

Using A Digital Multi Use Thermometer Rectally

This is the best method for taking the temperature of infants younger than three months, and perhaps all infants. Rectal temperature measurement is the closest to the infant’s core temperature. It is the core temperature, not the skin temperature, that tells us about the infant’s state of health. Before administering the temperature check, make sure it is set to Fahrenheit rather than Celsius. It is important to note that a rectal temperature might be higher than temperatures taken by other methods.

  • Step One: Clean the thermometer with isopropyl alcohol or anti-bacterial soap.
  • Step Two: Gently coat the end of the thermometer with a light glaze of petroleum jelly or a similar safe lubricant.
  • Step Three: Remove the baby’s diaper or any other clothing to give you full access to their bottom.
  • Step Four: Lay your infant on their stomach on a safe and comfortable surface.
  • Step Five: Gently hold your infant in place while you take the temperature.
  • Step Six: Activate the thermometer and insert it only half an inch to one inch into your infant’s rectum and wait for the thermometer to beep. If you feel resistance, stop pushing.
  • Step Seven: Gently remove the thermometer and read the temperature.

Other Methods For Taking An Infant’s Temperature

Temporal Artery Thermometers

These devices are designed to measure the temperature from the forehead, though they are not the most accurate for infants younger than 3 months old.

Tympanic Thermometers

This is a special device that is inserted into the infant’s ear. A disposal plastic cap protects the temperature probe. This method is not accurate for infants 6 months or younger.

How Should We Respond To An Infant With A Fever?

Newborn To 3 Months

Newborns, especially those less than six weeks old, may develop a perinatal infection that can progress rapidly and have serious outcomes. In this age group, contact your doctor IMMEDIATELY for further advice or to determine the best course of treatment.

Infant 3 Months & Older

A low-grade fever can often be treated at home. A persistent or high fever needs to be assessed by a pediatrician.

When Should I Take A Feverish Baby To A Doctor?

You should always contact a physician about any fever in a baby that is younger than 3 months old. For infants 3 to 6 months old, you should contact a doctor if they have a temperature of 102 degrees or greater, if they have elevated temperatures for more than a few days, or if they seem ill even if the temperature is lower.

If ever you are uncertain about whether or not to call for advice in managing an infant with fever, it is always best to call your pediatrician!

How To Make An Infant With Fever More Comfortable

A fever is a sign that something is not right, but the temperature itself may not be harmful to the child. As noted, an elevated temperature or low-grade fever in a child that is 3 months or older may not require a trip to the pediatrician. It is the discomfort associated with temperature elevation that we should seek to relieve. Here are some ways to help.

Adjust Their Clothing

Thick clothes and full-body footy pajamas can sometimes elevate your infant’s ambient body temperature. It might help to simply dress them in some lighter pajamas or switch them to a lighter blanket. This might also help your infant’s body to optimize its own natural ability to regulate body temperature.

Turn Down The Temperature In Their Room

Turning down the heat in your infant’s room can help prevent overheating. This too can help trigger their body’s own ability to regulate their temperature.

Administer A Recommended Dosage Of Acetaminophen

An infant over 3 months old can have a safe amount of children’s acetaminophen. The dosage is based on weight. So, if your child has had a recent growth spurt, you may want to weigh them first to determine the most accurate dosage. You can do this at home by first weighing yourself.

Then hold the baby and see the weight difference.

Infant Acetaminophen Dosing Chart for suspension liquid 160 mg/5ml – (source: AAP)

Baby’s weight / Dose (in milliliters)

  • 6-11 pounds / 1.25 ml
  • 12-17 pounds / 2.5 ml
  • 18-23 pounds / 3.75 ml
  • 24-35 pounds / 5 ml

Give Your Infant A Lukewarm Bath

First, give a dose of acetaminophen to lower the body’s set point of the temperature. Then, you can give them a gentle bath in their baby bathtub or a gentle sponge bath. The goal is to use water that feels warm, but not hot, to the touch on your inner arm. Avoid using alcohol wipes and cold water which can cause shivering (body’s attempt to return to an elevated set point) and may impede their natural temperature regulation.

Offer Plenty Of Fluids

Dehydration can complicate fever. Offer fluids such as breast milk or formula to help keep them properly hydrated. You should also watch to make sure that your baby has tears when crying, that their mouth is moist, and that they are having regular wet diapers.