Understanding fever in kids

August 05, 2015
As a Pediatric Emergency Physician in practice for 18 years, I have seen a great many children with fever. I also see a great many parents and other caregivers who are very concerned about fever, but are reassured when factual information about fever is provided to them.

Fever is a marker of illness and is very concerning in specific circumstances. Fever over 100.4 in any infant less than 60 days of age is reason to seek urgent medical evaluation. However, once children get beyond the newborn period, fever is much less concerning to medical professionals. The following information can help you better understand fever, and help you care for your child without unnecessary worrying. Fever myths lead to fever phobia while in fact, fevers are harmless and often helpful.

Let these facts help you better understand fever:

MYTH: My child feels warm, so she has a fever.
FACT: Children can feel warm for a many reasons. Examples are playing hard, crying, getting out of a warm bed or hot weather. They are "giving off heat". Their skin temperature should return to normal in 10 to 20 minutes. About 80% of children who act sick and feel warm do have a fever. If you want to be sure, take the temperature. These are the cutoffs for fever using different types of thermometers:
• Rectal, ear or forehead temperature: 100.4° F (38.0° C) or higher
• Oral (mouth) temperature: 100° F (37.8° C) or higher
• Under the arm (Armpit) temperature: 99° F (37.2° C) or higher

MYTH: Oral temperatures between 98.7° and 100° F (37.1° to 37.8° C) are low-grade fevers.
FACT: These temperatures are normal. The body's normal temperature changes throughout the day. It peaks in the late afternoon and evening. A true low-grade fever is 100° F to 102° F (37.8° - 39° C).

MYTH: All fevers are bad for children.
FACT: Fevers turn on the body's immune system. They help the body fight infection. Normal fevers between 100° and 104° F (37.8° - 40° C) are good for sick children.

MYTH: Fevers above 104° F (40° C) are dangerous. They can cause brain damage.
FACT: Fevers with infections don't cause brain damage. Only temperatures above 108° F (42° C) can cause brain damage. It's very rare for the body temperature to climb this high. It only happens if the air temperature is very high. An example is a child left in a closed car during hot weather.

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: 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: Once the fever comes down with medicines, it should stay down.
FACT: The fever will normally last for 2 or 3 days with most viral infections. Therefore, when the fever medicine wears off, the fever will return and need to be treated again. The fever will go away and not return once your child’s body overpowers the virus (usually by the fourth day).

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. The exact temperature number is not.

Keep in mind that fever is fighting off your child's infection. Fever is one of the good guys. These fever myths were excerpted from the Swedish Kids Symptom Checker – for more information on fever and other health information, or to download the symptom checker app for use on the go, click here.
Topics: Kids, Services