Fever: What You Need to Know

Fever is one of the most common reasons why parents bring their children to me for an evaluation. Many parents perceive fever as a disease and fear that it may cause harm or even death if it is not treated. In this article, I would like to dispel the fever phobia. 

What is fever?
Fever is an elevation of the body’s temperature in response to infection. A part of the brain called the hypothalamus serves as the body’s thermostat. It helps us maintain a normal temperature of about 98.6 F. Sometimes, the hypothalamus resets the body’s temperature in response to an infection. An elevated temperature stimulates the immune system to fight off the infection.

Your child has a fever when her temperature is:
• 100.4° Fahrenheit (38° Celsius) measured rectally
• 99.5° Fahrenheit (37.5° Celsius) measured orally
• 99° Fahrenheit (37.2° Celsius) measured under the arm

How to measure temperature?
Research indicates that evaluation of temperature by touch or kiss does not correlate with the actual body’s temperature. Therefore, it is important to measure it in a reliable way. Since pacifier, ear, or other newer thermometers have varied and have low sensitivity, the old-fashioned way of measuring your child’s temperature is recommended. For infants younger than 3 months, a rectal temperature should be measured. In children 3 months to 5 years, the temperature should be measured under the arm, and older children can have their temperature checked either under the arm or orally.

How to treat your child's fever?
Since fever activates the immune system in an attempt to fight off infection, its presence is very beneficial. However, I use general rules of thumb for fever treatment:

• If the fever is 102 F or higher, it should be treated
• Any fever below 102 F that makes your child uncomfortable should be treated

Help your feverish child feel better by offering plenty of fluids. When your child has a fever, her body uses more water. A dehydrated child will always feel worse, so let her sip water, Gatorade, or diluted juice. A sneaky way of getting fluids in is to let your child eat Popsicles and jello.

I do not recommend lukewarm baths for children running fevers, because they may get chilled. Shivering is caused by muscle contractions that produce heat; therefore, it tends to increase the body’s temperature. Instead, apply cool compresses to the neck, forehead, under the armpits, and the groin area. Skin is very thin in those places, thus blood vessels are close to the surface. The cooled down blood will be distributed throughout the body and help your child’s fever to go down.

Is alternating Tylenol and Motrin safe?
Alternating Tylenol and Motrin is not recommended. For higher fevers use ibuprofen (Motrin or Advil). For lower fevers, acetaminophen (Tylenol) should do the trick.
When should you see a health care provider?
When your child’s fever lasts for longer than 3 days, she should be evaluated by a health care provider. Viral infections may produce fevers typically lasting for up to 3 days. Fevers lasting longer than that may indicate your child has a bacterial infection and requires an antibiotic.

If the fever is high, 102 or higher, and you cannot control it with ibuprofen, take your child in to see her health care provider as well. She might have a bacterial infection.

All infants running a fever younger than 3 months of age need to be seen by a health care provider immediately to rule out meningitis.