A fever in a child is a temperature of 100.4°F (38.0°C) or higher measured rectally, and in most cases it’s a sign that your child’s body is fighting off an infection. The vast majority of childhood fevers resolve on their own within a few days and don’t need anything beyond fluids, rest, and comfort care. Your main job is to keep your child comfortable, watch for warning signs, and know when the situation calls for medical attention.
How to Take an Accurate Temperature
The method you use to take your child’s temperature matters, because readings vary by site. A rectal thermometer gives the most accurate reading and is recommended for children under 3 years old. Oral readings run about 0.7°F (0.4°C) lower than rectal, and armpit (axillary) readings run about 1.3°F (0.7°C) lower than rectal. So a 99.7°F armpit reading may actually reflect a true fever.
For babies and toddlers, use a digital rectal thermometer with a small amount of petroleum jelly on the tip. For children over 4 or 5 who can hold a thermometer under their tongue, oral readings are reliable. Ear thermometers work well for older infants and children but can give inconsistent results if not positioned correctly. Forehead (temporal) thermometers are convenient for a quick check, though less precise.
When a Fever Needs Immediate Attention
Your child’s age is the single most important factor in deciding how urgently to respond. Any baby under 3 months old with a rectal temperature of 100.4°F (38.0°C) or higher needs to be seen right away, even if they look fine. Young infants have immature immune systems, and a fever at this age can signal a serious bacterial infection. Your pediatrician or an emergency department will likely run blood and urine tests to rule out infection.
For babies between 3 and 6 months, a temperature of 102.2°F (39.0°C) or higher warrants a call to your pediatrician, even without other symptoms. For children 7 to 24 months old, contact your doctor if a rectal temperature above 102°F (38.9°C) lasts longer than one day with no other symptoms.
Regardless of age, head to the emergency room if your child has a fever along with any of these:
- Extreme drowsiness or difficulty waking up
- A stiff neck
- Difficulty breathing
- Blue lips, tongue, or nails
- Continuous, inconsolable crying
- A new rash that appears with the fever
- Seizures or convulsions
- Excessive drooling or trouble swallowing
- Abdominal pain or tenderness
- Confusion, altered speech, or strange behavior
Fever-Reducing Medication
Acetaminophen (Tylenol) can be given to children 2 months and older, and ibuprofen (Advil, Motrin) can be given to children 6 months and older. Always dose by your child’s weight, not their age. The weight-based dosing chart on the package is your best guide, and if you’re unsure, your pediatrician’s office can walk you through it over the phone.
Acetaminophen can be given every 4 to 6 hours. Ibuprofen can be given every 6 to 8 hours. Never give aspirin to children or teenagers, as it’s linked to a rare but serious condition called Reye’s syndrome.
Some parents alternate acetaminophen and ibuprofen to keep a fever down more consistently. Medical guidelines are mixed on this approach. Some recommend sticking with one medication at a time to reduce the risk of accidental overdosing, while others say alternating is acceptable when the child is very uncomfortable. A large review of studies found no difference in side effects between using one medication alone and alternating the two, as long as both are given at appropriate doses. If you want to alternate, write down what you gave and when so you don’t lose track.
One important point: the goal of medication is to make your child more comfortable, not to bring the number on the thermometer back to normal. A child whose fever drops from 103°F to 101°F but who is now drinking fluids and resting comfortably is doing well.
Keeping Your Child Comfortable at Home
Dress your child in light, breathable clothing. A single layer is usually enough. If your child has chills, it’s fine to add a light blanket, but avoid piling on heavy covers, which can trap heat and push the temperature higher.
A cool, damp washcloth on the forehead or the back of the neck can feel soothing. Room-temperature baths that feel slightly cool to the touch can also help. Skip cold baths, ice packs, and alcohol rubs. These can cause shivering, which actually raises body temperature, and alcohol rubs are dangerous for children because the fumes can be inhaled.
Keep the room at a comfortable temperature. If your child is shivering and feels cold despite a high reading, hold off on active cooling. Trying to cool a child who has chills will only make them more miserable.
Fluids and Watching for Dehydration
Fever increases fluid loss, so your child needs to drink more than usual. Water, diluted juice, breast milk, formula, ice chips, and popsicles all count. Don’t worry too much about food if your child isn’t hungry. Hydration is more important in the short term.
Watch for signs that your child is getting dehydrated:
- Dry mouth and lips
- Few or no tears when crying
- Fewer wet diapers than usual (or fewer bathroom trips for older kids)
- Sunken-looking eyes
Mild dehydration can usually be corrected at home with small, frequent sips. If your child has no tears at all when crying, hasn’t had a wet diaper in several hours, or the dry mouth and reduced urination aren’t improving with fluids, that’s a sign of more significant dehydration and a reason to call your doctor.
What to Do if Your Child Has a Seizure
Febrile seizures happen when a burst of electrical activity in the brain is triggered by a fever. They affect about 2 to 5 percent of children between 6 months and 5 years old, and while they look terrifying, the vast majority are harmless and don’t cause lasting damage. A typical febrile seizure involves uncontrollable shaking, eye rolling, and a brief loss of consciousness.
If it happens, stay calm and do the following: gently lay your child on the floor on their side so they won’t choke if they vomit. Don’t place them on a bed or table where they could fall. Don’t try to hold them down or put anything in their mouth. Note the time the seizure starts. Most febrile seizures last under five minutes and stop on their own. If it goes beyond five minutes, call 911.
After a first febrile seizure, contact your pediatrician. They’ll want to examine your child and may look for the source of the fever, but in most cases no further treatment is needed.
How Long a Fever Typically Lasts
Most childhood fevers caused by common viral infections last two to three days. Some can stretch to five days depending on the virus. A fever that persists beyond three days, even if your child seems otherwise okay, is worth a call to your pediatrician. The same applies if a fever goes away for a day or more and then returns, which can sometimes signal a secondary infection.
During the fever, your child’s temperature will naturally rise and fall throughout the day. It tends to be lowest in the morning and highest in the late afternoon and evening. Don’t be alarmed if the fever spikes after seeming to improve earlier in the day. Focus less on the exact number and more on how your child is acting. A child with a 103°F fever who is still drinking, making eye contact, and responding to you is generally in a better spot than a child with a 101°F fever who is limp and unresponsive.