Fever Facts and Myths

Misconceptions about the dangers of fever are commonplace. Unwarranted fears about harm from normal fevers causes lost sleep and unnecessary stress for many parents. Let the following facts help you put fever into perspective:

MYTH:  My child feels warm, so she has a fever.

FACT:  Children can feel warm for a many reasons such as playing hard, crying, getting out of a warm bed, or being outside on a hot day. They are “giving off heat.” Their skin temperature should return to normal in 10 to 20 minutes. Once these causes are excluded, about 80% of children who feel warm and act sick actually have a fever. If you want to be sure, take their temperature. The following are the cutoffs for fever using different types of thermometers:

  • Rectal, ear or temporal artery thermometers: 100.4° F (38.0° C) or higher
  • Oral or pacifier thermometers: 100° F (37.8° C) or higher
  • Axillary (armpit) temperatures: 99° F (37.2° C) or higher

MYTH: All fevers are bad for children.

FACT:  Fevers turn on the body’s immune system. Fevers are one of the body’s protective mechanisms. Normal fevers between 100° and 104° F (37.8° – 40° C) are usually good for sick children and help the body fight infection.

MYTH:  Fevers cause brain damage or fevers above 104° F (40° C) are dangerous.

FACT:  Fevers with infections don’t cause brain damage. Only body temperatures above 108° F (42° C) can cause brain damage. the body temperature climbs this high only with extreme environmental temperatures (for example, if a child is confined to a closed car in hot weather).

MYTH: Anyone can have a febrile seizure (seizure triggered by fever).

FACT:  Only 4% of children can have a febrile seizure.

MYTH:  Febrile seizures are harmful.

FACT:  Febrile seizures are scary to watch, but they usually stop within 5 minutes. They cause no permanent harm. Children who have had febrile seizures do not have a greater risk for developmental delays, learning disabilities, or seizures without fever.

MYTH: All fevers need to be treated with fever medicine.

FACT:  Fevers only need to be treated if they cause discomfort. Usually fevers don’t cause any discomfort until they go above 102° or 103° F (39° or 39.5° C).

MYTH:  Without treatment, fevers will keep going higher.

FACT:  Wrong. Because the brain has a thermostat, fevers from infection usually top out at 103° or 104° F (39.5°- 40° C). They rarely go to 105° or 106° F (40.6° or 41.1° C). While the latter are “high” fevers, they are harmless ones.

MYTH:  With treatment, fevers should come down to normal.

FACT:  With treatment, fevers usually come down 2° or 3° F (1° or 1.5° C).

MYTH:   If the fever doesn’t come down (if you can’t “break the fever”), the cause is serious.

FACT:  Fevers that don’t respond to fever medicine can be caused by viruses or bacteria. It doesn’t relate to the seriousness of the infection.

MYTH:  If I can “break the fever”, the infection will go away.

FACT:  The fever will normally last for 2 or 3 days until the body turns off the virus’s attack and gets the upper hand. This process cannot be hurried. The source of this misconception is that during an infection, when the fever goes away, the child is usually on the road to recovery. It’s magical thinking, however, to assume that making the fever go away earlier (which is impossible), will make the infection go away earlier too.

MYTH:  If the fever is high, the cause is serious.

FACT:  If the fever is high, the cause may or may not be serious. If your child looks very sick, the cause is more likely to be serious.

MYTH:  The exact number of the temperature is very important.

FACT:  How your child looks is what’s important, not the exact temperature.

MYTH:  Oral temperatures between 98.7° and 100° F (37.1° to 37.8° C) are low-grade fevers.

FACT:  Wrong, these temperatures are normal variations. The body’s temperature normally changes throughout the day. It peaks in the late afternoon and evening. An actual low-grade fever is 100° F to 102° F (37.8° – 39° C).

SUMMARY: Remember that fever is fighting off your child’s infection. Fever is one of the good guys.

Disclaimer:This information is not intended be a substitute for professional medical advice. It is provided for educational purposes only. If you have concerns about your child’s fever, make an appointment to see your doctor.

Copyright 1994-2015 Barton D. Schmitt, MD. All rights reserved. Shared from Seattle Children’s Hospital (seattlechildrens.org).