A fever is usually a sign that the body is fighting an illness or infection. Fevers are generally harmless. In fact, they can be considered a good sign that your child's immune system is working and the body is trying to heal itself. While it is important to look for the cause of a fever, the main purpose for treating it is to help your child feel better if he is uncomfortable or has pain.

Read on to find out more from the American Academy of Pediatrics (AAP) about how to tell if your child has a fever and how to manage a fever.

What is a fever?

Normal body temperature varies with age, general health, activity level, and time of day. Infants tend to have higher temperatures than older children. Everyone's temperature is highest between late afternoon and early evening, and lowest between midnight and early morning. Even how much clothing a person wears can affect body temperature.

A fever is a body temperature that is higher than normal. While the average normal body temperature is 98.6°F (37°C), a normal temperature range is between 97.5°F (36.4°C) and 99.5°F (37.5°C). Most pediatricians consider a temperature 100.4°F (38°C) or higher a sign of a fever (see "Taking Your Child's Temperature").

Signs and symptoms of a fever

If your child has a fever, she may feel warm, appear flushed, or sweat more than usual. She may also be more thirsty than usual.

Some children feel fine when they have a fever. However, most will have symptoms of the illness that is causing the fever. Your child may have an earache, a sore throat, a rash, or a stomachache. These signs can provide important clues as to the cause of the fever.

When to call the doctor

The most important things you can do when your child has a fever are to improve your child's comfort by making sure they drink enough fluids to stay hydrated and monitor for signs and symptoms of a serious illness. It is a good sign if your child plays and interacts with you after receiving medicine for discomfort.

Call your child's doctor right away if your child has a fever and

• Looks very ill, is unusually drowsy, or is very fussy

• Has been in a very hot place, such as an overheated car

• Has other symptoms, such as a stiff neck, severe headache, severe sore throat, severe ear pain, an unexplained rash, or repeated vomiting or diarrhea

• •Has immune system problems, such as sickle cell disease or cancer, or is taking steroids or other medicines that could affect his immune system

• Has had a seizure

• Is younger than 3 months (12 weeks) and has a temperature of 100.4°F (38.0°C) or higher

• •Fever rises above 104°F (40°C) repeatedly for a child of any age

Also call your child's doctor if

• Your child still "acts sick" once his fever is brought down.

• Your child seems to be getting worse.

• The fever persists for more than 24 hours in a child younger than 2 years.

• The fever persists for more than 3 days (72 hours) in a child 2 years of age or older.

Treating your child's fever

If your child is older than 6 months and has a fever, she probably does not need to be treated for the fever unless she is uncomfortable. Watch her behavior. If she is drinking, eating, sleeping normally, and is able to play, you should wait to see if the fever improves by itself and do not need to treat the fever.

What you can do

• Keep her room comfortably cool.

• Make sure that she is dressed in light clothing.

• Encourage her to drink fluids such as water, diluted juices, or a store-bought electrolyte solution.

• Be sure that she does not overexert herself.

• See “How to improve your child’s comfort with medicine”

Taking your child’s temperature

While you often can tell if your child is warmer than usual by feeling his forehead, only a thermometer can tell how high the temperature is. Even if your child feels warmer than usual, you do not necessarily need to check this temperature unless he has other signs of illness described above.

Always use a digital thermometer to check your child’s temperature (see “Types of digital thermometers” chart for more information, including guidelines on what type of thermometer to use by age). Mercury thermometers should not be used. The AAP encourages parents to remove mercury thermometers from their homes to prevent accidental exposure and poisoning.

Note: Temperature readings may be affected by how the temperature is measured and other factors (see “What is a fever?”). Your child’s temperature and other signs of illness will help your doctor recommend treatment that is best for your child.

Types of digital thermometers

The following are 3 types of digital thermometers. While other methods for taking your child’s temperature are available, such as pacifier thermometers or fever strips, they are not recommended at this time. Ask your child’s doctor for advice.

How to use a digital multiuse thermometer

How to improve your child’s comfort with medicine

Acetaminophen and ibuprofen are safe and effective medicines if used as directed for improving your child’s comfort, and they may also decrease the fever. They do not need a prescription and are available at grocery stores and drugstores. However, keep the following in mind:

• Ibuprofen should only be used for children older than 6 months. It should not be given to children who are vomiting constantly or are dehydrated.

• Do not use aspirin to treat your child’s fever or discomfort. Aspirin has been linked with side effects such as an upset stomach, intestinal bleeding and, most seriously, Reye syndrome.

• If your child is vomiting and cannot take anything by mouth, a rectal suppository may be needed. Acetaminophen comes in suppository form and can help reduce discomfort in a vomiting child.

Before giving your child any medicine, read the label to make sure that you are giving the right dose for his age and weight. Also, if your child is taking other medicines check the ingredients. If they include acetaminophen or ibuprofen, let your child’s doctor know. To be safe, talk with your child’s doctor before giving your child any medicine to treat discomfort or a fever if he is younger than 2 years. (Note: In 2011 manufacturers began replacing infant acetaminophen drops 80 mg/0.8 mL with infant or children acetaminophen liquid 160 mg/5 mL. Visit HealthyChildren.org at www.healthychildren.org/feverpain for more information. If giving acetaminophen, be sure to tell your child’s doctor if you are using infant drops 80 mg/0.8 mL or infant or children’s liquid 160 mg/5 mL.)

Should sponging be used to reduce a fever?

It is not recommended that you use sponging to reduce your child’s fever. There is no information that shows that sponging or tepid baths improve your child’s discomfort associated with a fever or illness. Cool or cold water can cause shivering and increase the temperature. Never add rubbing alcohol to the water. Rubbing alcohol can be absorbed into the skin or inhaled, causing serious problems such as a coma.

What if my child has a febrile seizure?

In some children younger than 6 years, fever can trigger seizures. While this can be frightening, these seizures are usually harmless. During a seizure your child may look strange for a few minutes; shake; then stiffen, twitch, and roll his eyes. The color of his skin may also change and appear blue. If this happens,

• Place him on the floor or bed, away from any hard or sharp objects.

• Turn his head to the side so that any saliva or vomit can drain from his mouth.

• Do not put anything into his mouth, not even a finger.

• Call your child’s doctor.

Your child’s doctor will want to check your child, especially if it is his first seizure. It is important to look for the cause of the febrile seizure.

If your child has had a febrile seizure in the past, treating your child with acetaminophen or ibuprofen when he has another fever will not prevent another febrile seizure from occuring. Discuss this at your child’s next well-visit.

Digital thermometer drawings by Anthony Alex LeTourneau