Fevers (for Parents) - Nemours KidsHealth

Top Things to Know

• A fever is usually a temperature of 100.4°F (38°C) or higher, depending on how it's measured.
• Most fevers are caused by infections and help the body fight off germs.
• Symptoms may include warmth, crankiness, chills, headache, and flushed skin.
• Keep kids comfortable with light clothing, rest, and plenty of fluids.

Signs & Symptoms

What Are the Signs and Symptoms of a Fever?

Here are fever symptoms to watch for in kids:

• feeling warm
• acting differently (they might be fussy or cranky, or quieter than usual)
• breathing a little faster or having a faster heart rate than normal
• having a headache
• having chills or sweating
• having red or flushed skin

For any of these signs, take your child’s temperature to know if it’s really a fever.

When to Go to the Emergency Room or Call the Doctor

Go to the ER if your child has a fever and:

• is crying nonstop or is extremely cranky or fussy
• is sluggish and hard to wake up
• has purple spots that look like bruises
• has blue lips, tongue, or nails
• has a bulging or sunken soft spot on the head (in babies)
• has a stiff neck, severe headache, or bad belly pain
• is limp or refuses to move
• has trouble breathing that doesn’t get better when the nose is cleared
• has a seizure

Call your doctor right away if your child:

• is younger than 3 months old with a temperature of 100.4°F (38°C) or higher. If you can’t reach your doctor, go to the emergency room (ER).
• is any age but has a health problem like cancer or sickle cell disease and has a fever

If your child has an ongoing health issue, make sure you know when the doctor should be called for fever.

Call your doctor if your child is 3 months or older, has a fever, and:

• doesn’t want to drink or seems too sick to drink enough
• has lasting diarrhea or repeated vomiting
• seems dehydrated, like urinating (peeing) less, not having tears when crying, or being less alert and less active
• has a specific complaint, like a sore throat, an earache, or pain with peeing
• has a rash
• the fever last longer than 2–3 days
• fever keeps going above 104°F (40°C)
• looks really sick to you or seems to be getting worse

When Is a Fever Probably Not Serious?

A fever is likely not serious if your child is 3 months or older and:

• is still interested in playing
• is drinking well
• is alert and smiling
• has normal skin color
• looks well when the temperature comes down

It’s normal for kids with a fever to eat less. This is common with infections that cause fever. As long as your child is drinking and peeing normally, not eating as much as usual is OK.

Causes

What Causes a Fever?

The most common cause of fever is an infection, but one can also be caused by:

• Overdressing. Infants, especially newborns, may get fevers if they're overdressed, wrapped in a blanket, or in a hot environment because they don't regulate (control) their body temperature as well as older kids. But because fevers in newborns can be a sign of a serious infection, even infants who are overdressed must be checked by a doctor if they have a fever.
• Vaccines. Babies and kids sometimes get a mild fever that lasts about a day after getting vaccinated.
• Teething. A child who has a tooth or teeth coming in might have a slight rise in body temperature, but it's probably not the cause if the temperature is higher than 100°F (37.8°C).

How Should I Take My Child's Temperature?

If your child feels warm or is acting unwell, use a digital thermometer to check for a fever. Some ways of taking a temperature are more accurate than others at measuring the true body temperature.

The best way to take a temperature:

• For kids 3 years old and younger: in the bottom
• For kids 4 or older who can cooperate: by mouth
• For any age: The forehead and under the armpit are easiest but not always as accurate. In the ear is OK for kids 6 months and older.