A child's fever: when to worry

Fevers can be a scary thing for parents. Watching your children suffer – whether you’re a new parent or not – is never easy. And when they are sick with a fever, sometimes you don’t know what to do or where to go.

Whatever the thermometer reads, there are several factors to consider before you call your child’s pediatrician or visit an urgent care center or emergency room.

A child’s age, symptoms, and temperature reading all determine your next steps.

Understanding Fevers

Learning why fevers occur and what to look for will help you feel more equipped to handle the next one.

Your child’s average body temperature is 98.6 degrees Fahrenheit. This reading can fluctuate throughout the day, ranging from 97.4 to 99.6 degrees Fahrenheit.

A temperature of higher than 99 degrees Fahrenheit is a sign that your child’s body is fighting an infection. The immune system releases chemicals when there is an infection, which raise the body’s internal temperature. A low-grade fever doesn’t necessarily indicate a serious situation — just as an absence of a fever doesn’t necessarily mean there isn’t a problem.

Typically, most fevers go away in three to four days and require nothing more than proper hydration, over-the-counter medication and rest.

Depending on the age of your child and how high the temperature, you may want to allow nature to take its course. Or you may need to take action.

Several factors, including easing your child’s discomfort, will determine your next steps.

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How Age Impacts Treatment of Fevers

Typically, the younger the child, the quicker the response.

If your infant is under 3 months of age and has a fever of 100.4° Fahrenheit or higher, you should seek immediate medical attention.

Illnesses can escalate quickly, and a baby’s immune system is not as robust as an older child’s. Notify your child’s pediatrician so that your child can be evaluated either in the office or at the ER. Avoid the temptation to administer any fever-reducing medications until your child has been seen by a doctor.

Also, make sure you take their temperature rectally for the most accurate reading.

If your child is between the ages of 3 months and 3 years old and has a fever of 102.2° Fahrenheit (39°Celsius) or higher, contact your child’s pediatrician to determine if your child should be seen. When it comes to older kids, their behavior and activity level speaks volumes. You know your child best, so you’ll have a good idea as to whether you’re dealing with a minor illness or if a doctor’s visit is necessary.

If your child demonstrates the following with an elevated body temperature, it’s probably not serious and needs to run its course:

  • Remains interested in playing or normal activities.
  • Continues eating and drinking well with light-colored urine (indicating proper hydration).
  • Is smiling and awake/aware of their surroundings.
  • Appears normal in skin color/overall appearance.
  • Has improved behavior and appearance when their fever drops.

Many times, fevers occur in the middle of the night, creating panic and uncertainty about how to treat them.

Again, the age and accompanying symptoms will determine whether you should wait to contact your child’s pediatrician in the morning or take your child to an ER. Follow your doctor’s advice in treating the fever at home based on your specific situation and make an appointment to see the doctor the next day. In the early evening hours, your doctor’s office likely has an on-call physician ready to take calls after-hours so they can best direct you to the right care in the right place.

When kids have a fever, they often are fussy, not eating, and visibly uncomfortable.

However, if your child has any of the following symptoms, call your child’s pediatrician immediately:

  • Fevers of 104° F (40° C) — or higher that do not drop despite your at-home treatment measures.
  • Lethargy – This is not simply fatigue. In this instance, your child is limp, almost unresponsive and won’t make eye contact.
  • Irritability – Again, this not just discomfort or fussiness. A truly irritable child will cry for hours with little to no verbal interaction and is almost impossible to calm down.
  • Meningitis – While there is a vaccination given to avoid this serious illness, symptoms include high fever, stiff neck or pain in the back of the neck, vomiting, headache, and eye pain in bright light. Check for and record any other symptoms your child has, such as cough, vomiting, rash, etc., and inform your child’s pediatrician.

Causes of High Fever in Children

If your child has a fever, chances are high that one of the following conditions caused it:

Viral Infection

Viruses are the most common cause of fever in children, and they do not require antibiotics. A virus must run its course over several days. These infections include:

  • Colds.
  • Flu.
  • Roseola.
  • Chicken pox.
  • Hand, foot, and mouth disease.
  • Fifth disease.

Bacterial Infection

Treatable with antibiotics and contagious, bacterial infections can wait for 12 hours until your child is seen by a doctor. Common examples are:

  • Ear infection
  • Sinus infection
  • Pneumonia
  • Bladder infection
  • Strep throat

Taking Your Child’s Temperature

You can use the following methods to take your child’s temperature:

1. Regular glass underarm thermometer — While old fashioned, the axillary method still may be the most accurate. It’s also one of the most difficult to use when you have an upset, mobile child. To take an axillary temperature, hold the thermometer in place for three minutes, making sure the tip is deep in the soft skin of the underarm or armpit.

2. Ear thermometer — An increasingly popular, quick, and easy method using an infrared sensor to measure the temperature of energy radiating from the ear drum. While the eardrum is an accurate point to measure body temperature, one ear may read several degrees different from the other. The rule of thumb is if it reads close to normal, it’s probably true. If it reads 103° F (39.5° C) or greater, confirm the reading with a glass underarm thermometer.

3. Digital thermometer — A kind of thermometer that may be used for an oral, underarm, or rectal readings. They are much faster than glass thermometers, although you do lose some accuracy, as with the ear thermometer.

4. Forehead thermometer — Seen in most pediatrician’s offices, this method of reading the child’s temperature is painless, not scary, and pretty accurate. Similar to the ear thermometer, it uses infrared technology to measure the body’s core temperature.

5. Pacifier thermometer — A non-invasive tool readily accessible and seen as an acceptable method of taking a child’s temperature.

At-Home Relief for Fevers

If your child is otherwise healthy and not under 3 months of age or exhibiting any of the other serious symptoms that requires immediate attention, you can ease the discomfort a fever brings. As always, check with your child’s pediatrician to ensure you are doing the right things for your child’s specific condition and overall health.

When it comes to giving the right amount of medicine, always dose by your child’s weight and not their age.


    • Acetaminophen – This fever reducer/pain reliever has been around a long time and is effective in most cases. It may be used in conjunction with ibuprofen by alternating between the two over the recommended dosage timeframe. This medication also can help ease body aches.
    • Ibuprofen – This medication also is effective for fever and pain. It often works better for higher fevers and lasts longer, too. It may be used in conjunction with acetaminophen by alternating between the two over the recommended dosage timeframe.
    • WARNING – Don’t give aspirin to children ages 12 and under. Reye’s syndrome is a serious but rare disorder that causes brain and liver damage. It occurs in children who’ve had recent viral infections. Those taking aspirin to treat an infection are at greater risk of Reye’s syndrome.
    • Keeping your child’s energy up is important. If your child is vomiting and can’t keep down any medication, you can use acetaminophen suppositories available at your local pharmacy. Suppositories are given into the child’s rectum. Replace nutrients once the stomach has settled down with bland foods, such as crackers, applesauce, rice, and toast. Their appetite likely won’t be strong and that’s OK. It’s more important to keep your child hydrated. Avoid anything with spice, dairy, or citrus which can aggravate the stomach.

Lukewarm bath and cool compresses

Although it may not be the most comfortable feeling with a higher body temperature, a cool — not cold — bath can help reduce a fever quickly. It’s recommended that you use a cool bath along with a fever-reducing medication and not in place of it. Applying a cool washcloth on their forehead also may bring some relief.

Cool liquids

Drinking cool liquids can help lower a fever and will keep your child well-hydrated. Give Pedialyte to restore electrolytes and plenty of water.

How long do fevers last?

Most fevers and accompanying cold-like symptoms can last from three to five days. If your child’s fever lasts longer than that, they should see the doctor to eliminate any risk of complications. Consult your pediatrician if your child’s symptoms are worsening or the fever is climbing despite the use of at-home remedies.

Call Your Doctor

If your child is between the ages of 3 months and 3 years old and exhibits fever lower than 102.2 degrees Fahrenheit, but also:

  • Refuses fluids or appears too ill to drink enough to stay hydrated.
  • Has lasting diarrhea or repeated vomiting.
  • Shows signs of dehydration (peeing less than usual, no tears when crying, less alert and less active than usual).
  • Has a specific complaint (like a sore throat or earache).
  • Maintains a fever after 24 hours (in kids younger than 2 years old) or 72 hours (in kids 2 years or older).
  • Is getting fevers a lot, even if they only last a few hours each night.
  • Has a chronic medical problem, such as heart disease, cancer, lupus, or sickle cell disease.
  • Develops a rash.
  • Experiences pain when urinating.

Visit the Emergency Room

If your child experiences any of these symptoms:

  • Nonstop crying.
  • Trouble breathing (after nose is cleared).
  • Blue lips, nails, or tongue.
  • Extreme irritability.
  • Trouble waking up or refusal to move.
  • New, sudden rash or purple spots that mimic bruises on the skin.
  • Soft spot on the head seems to be bulging out or sunken in.
  • Stiff neck.
  • Severe headache.
  • Leaning forward and drooling.
  • Seizures (can occur in children with fevers at 105° F or higher).
  • Abdominal (belly) pain.

Temperature Ranges

  • Temperatures between 99 -100° F generally are not cause for concern. This can be normal temperature variation during the day and can be monitored at home until evaluated by your doctor.
  • Fevers of 100.4 to 103° F should be discussed with your child’s provider. The provider will help determine next steps. 
  • High child fevers of 104° F or higher, that quickly come down to 100 or 101° with the treatment measures described, are also generally not serious and can wait until morning, unless your child is 3 months or younger.

Editor's Note: This article was originally published on , and was last reviewed on .

About UPMC

Headquartered in Pittsburgh, UPMC is a world-renowned health care provider and insurer. We operate 40 hospitals and 800 doctors’ offices and outpatient centers, with locations throughout Pennsylvania, Maryland, New York, West Virginia, and internationally. We employ 4,900 physicians, and we are leaders in clinical care, groundbreaking research, and treatment breakthroughs. U.S. News & World Report consistently ranks UPMC Presbyterian Shadyside as one of the nation’s best hospitals in many specialties and ranks UPMC Children’s Hospital of Pittsburgh on its Honor Roll of America’s Best Children’s Hospitals. We are dedicated to providing Life Changing Medicine to our communities.

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