Fever: When or If to Worry!


Fever is a “symptom” and is your body’s normal response to infections.  Fever also plays a role in fighting infections and helps to “turn on” your child’s immune system.   Fever, in of itself, is not dangerous.  How high your child’s temperature is not a measure of how sick your child is.  It is much more important to see how your child is acting and how he responds to treating his fever than to worry how high the fever is.

The average body temperature if taken in the mouth is 98.6 degrees Fahrenheit.  The most accurate way to take a temperature in and infant and young child is rectally.  Most children’s temperature changes throughout the day due to activity, excessive clothing, hot bath or drinking warm fluids.  If you think this might be the reason for your child’s fever, retake it in again in 30 minutes.

Your child has a fever if:
            Rectal:  > 100.4 degrees F
            Oral:  > 99.5 degrees F
            Auxiliary: (under arm)  > 98.6 degrees

Most fevers in children are caused by viral illnesses.  These fevers usually range at 101-104 degrees F and last 2-3 days.  Parents worry that their child will have a seizure with a high fever. These are called febrile seizures and, although they are scary when they occur, they are not dangerous to the child. Only about 4% of children with fevers will have a seizure.  Again, having a seizure is not a measure of how sick the child is. 

Bacterial infections can also cause a fever. Generally, your child will have a persistent fever longer than 3-4 days and worsening other symptoms.  Children should be evaluated if  fever persists for more than 4 days or sooner if symptoms are significant enough to interfere with breathing, taking feeds/fluids, activity or sleep.  Some children that are very sick may not have a high fever so again, much more important to see how your child is acting to decide when the child should be seen by a provider.

Medications: Remember fever is helpful to your child to fight infection so only use medication for fever when temperature is greater than 102 degrees F. This is usually when children are fussy and uncomfortable, so by reducing fever, they are more likely to drink fluids for you and act more themselves. Most of these medications will reduce the fever by a few degrees in about 2 hours but will need to be repeated at the appropriate times as the illness runs its course.

  • Acetaminophen:  > 2 months (unless directed by nurse/provider)
  • Ibuprofen:  > 6 months old
Please use this dosage chart from healthychildren.org.

**Aspirin products should never be used when a child has a fever or suspected viral illness (including chickenpox, influenza, sore throats) as this has been linked with a rare but severe illness called Reye’s Syndrome which can cause brain damage in children.  Medications such as Pepto-Bismol contain an aspirin product and should not be used in children with any viral illnesses.

Supportive home measures are important to help to control fever.  Fevers cause children to lose body fluid through sweating and therefore, so remember to encourage extra fluids.    It is also helpful to remove clothing and blankets to allow the fever to begin to reduce. Keeping your child bundled can cause the fever to get higher.   If your child begins to shiver, cover with a light blanket.

Children with fevers should be seen immediately for any of the following characteristics:
            Less than 2 months of age (without recent vaccination)
            Fever > 105
            Inconsolable crying
            Lethargy (difficult to awaken or behavior change) despite treatment of fever
            Stiff neck despite treatment of fever
            Purple spots or rash on skin
            Acts or looks very sick after treatment for fever
            Fever > 24 hours without any other symptoms
            Urinary symptoms
            History of febrile seizures
            Any additional concern

Remember, we always have a nurse you can speak with in our office during office hours and afterwards through our night call system.  Do not hesitate to call for any questions related to fever!

Respectively submitted by Cathy Stange CPNP at Alaska Center for Pediatrics

Reference: Barton Schmitt "Instructions for the Pediatric Patient"