Fever

A fever is a temperature of 100.4°F (38°C) or higher. Fevers are usually a sign that the body is fighting an infection. A fever on its own is rarely harmful. How the person looks and acts usually matters more than the number.

Taking a temperature

• For babies under 3 months, a rectal temperature is the most accurate.
• For older children and adults, mouth, ear, forehead, or rectal thermometers all work. Armpit readings are less accurate.
• Write down the temperature, the time, and any medicine given.

What to do

1. Drink plenty of fluids to avoid dehydration.
2. Rest.
3. Dress in light clothing. Use a light blanket if you have chills.
4. Use fever medicine if you or your child is uncomfortable. Acetaminophen or ibuprofen can help. Follow the package directions for age and weight, or ask a pharmacist. Don’t take more than one product with the same ingredient.
5. Watch for warning signs (see the boxes on this page).

For babies and children

• Call the doctor right away for any fever in a baby under 3 months. Don’t give fever medicine to a baby this young unless a doctor tells you to.
• Ibuprofen isn’t for babies under 6 months. Ask a doctor before giving any fever medicine to a baby under 6 months.
• Never give aspirin to children or teens. It is linked to Reye’s syndrome, a rare but serious illness.
• Use the dosing tool that comes with the medicine. Dose by weight if the label shows it.
• Don’t bundle a child in heavy blankets or use cold baths or rubbing alcohol to cool them.
• A child who is playing, drinking, and making eye contact after the fever comes down is usually doing OK.