Fever, Child

A fever is a higher than normal body temperature. A normal temperature is usually 98.6° F (37° C). A fever is a temperature of 100.4° F (38° C) or higher taken either by mouth or rectally. If your child is older than 3 months, a brief mild or moderate fever generally has no long-term effect and often does not require treatment. If your child is younger than 3 months and has a fever, there may be a serious problem. A high fever in babies and toddlers can trigger a seizure. The sweating that may occur with repeated or prolonged fever may cause dehydration.

A measured temperature can vary with:

  • Age.

  • Time of day.

  • Method of measurement (mouth, underarm, forehead, rectal, or ear).

The fever is confirmed by taking a temperature with a thermometer. Temperatures can be taken different ways. Some methods are accurate and some are not.

  • An oral temperature is recommended for children who are 4 years of age and older. Electronic thermometers are fast and accurate.

  • An ear temperature is not recommended and is not accurate before the age of 6 months. If your child is 6 months or older, this method will only be accurate if the thermometer is positioned as recommended by the manufacturer.

  • A rectal temperature is accurate and recommended from birth through age 3 to 4 years.

  • An underarm (axillary) temperature is not accurate and not recommended. However, this method might be used at a child care center to help guide staff members.

  • A temperature taken with a pacifier thermometer, forehead thermometer, or "fever strip" is not accurate and not recommended.

  • Glass mercury thermometers should not be used.

Fever is a symptom, not a disease.


A fever can be caused by many conditions. Viral infections are the most common cause of fever in children.


  • Give appropriate medicines for fever. Follow dosing instructions carefully. If you use acetaminophen to reduce your child's fever, be careful to avoid giving other medicines that also contain acetaminophen. Do not give your child aspirin. There is an association with Reye's syndrome. Reye's syndrome is a rare but potentially deadly disease.

  • If an infection is present and antibiotics have been prescribed, give them as directed. Make sure your child finishes them even if he or she starts to feel better.

  • Your child should rest as needed.

  • Maintain an adequate fluid intake. To prevent dehydration during an illness with prolonged or recurrent fever, your child may need to drink extra fluid. Your child should drink enough fluids to keep his or her urine clear or pale yellow.

  • Sponging or bathing your child with room temperature water may help reduce body temperature. Do not use ice water or alcohol sponge baths.

  • Do not over-bundle children in blankets or heavy clothes.


  • Your child who is younger than 3 months develops a fever.

  • Your child who is older than 3 months has a fever or persistent symptoms for more than 2 to 3 days.

  • Your child who is older than 3 months has a fever and symptoms suddenly get worse.

  • Your child becomes limp or floppy.

  • Your child develops a rash, stiff neck, or severe headache.

  • Your child develops severe abdominal pain, or persistent or severe vomiting or diarrhea.

  • Your child develops signs of dehydration, such as dry mouth, decreased urination, or paleness.

  • Your child develops a severe or productive cough, or shortness of breath.


  • Understand these instructions.

  • Will watch your child's condition.

  • Will get help right away if your child is not doing well or gets worse.