A fever in a child is almost always a sign that their body is fighting off an infection, and in most cases it resolves on its own within a few days. A temperature of 100.4°F (38°C) or higher, measured rectally, counts as a fever. The most important thing you can do is keep your child comfortable, watch for warning signs, and know when the fever needs medical attention.
How to Tell if It’s Actually a Fever
The number that counts as a fever depends on how you take the temperature. A rectal, ear, or forehead reading of 100.4°F (38°C) or higher is a fever. An oral reading of 100°F (37.8°C) or higher qualifies. An armpit reading of 99°F (37.2°C) or higher suggests a fever, though armpit readings are the least reliable.
For babies under 3 months, a rectal thermometer gives the most accurate result and is the recommended method. For older children, oral or forehead thermometers work well. Armpit readings can be a reasonable starting point for toddlers who resist other methods, but if the number looks borderline, confirm it with a more accurate method.
The One Rule That Matters Most: Age
If your baby is younger than 2 months old and has a rectal temperature of 100.4°F or higher, this is a medical emergency. Go to the emergency room right away, even if the baby seems fine otherwise. At this age, a fever can signal a serious bacterial infection, and hospitals follow a specific protocol that includes blood work and other testing to rule out dangerous causes. Do not give fever-reducing medicine and wait to see what happens.
For babies 2 to 3 months old, call your pediatrician immediately with any fever. They’ll tell you whether to come in or head to the ER. Once a child is older than 3 months, a fever alone is less alarming, and how your child looks and acts matters more than the number on the thermometer.
Keeping Your Child Comfortable at Home
A fever doesn’t always need to be treated with medicine. If your child is playing, drinking fluids, and seems relatively normal, you can simply monitor them. The goal of treatment isn’t to bring the temperature back to 98.6°F. It’s to help your child feel well enough to rest and stay hydrated.
Dress your child in lightweight, breathable clothing. If they have chills, a light blanket is fine, but avoid bundling them up in heavy layers. Offer small, frequent sips of fluids throughout the day. Water, diluted juice, breast milk, formula, and popsicles all count. Keeping fluid intake steady is one of the most important things you can do, because fevers increase the body’s water needs.
Skip the cold baths or alcohol rubs, which are outdated approaches. A lukewarm washcloth on the forehead can feel soothing, but it won’t significantly lower the temperature. Let your child rest as much as they want to, but don’t force bed rest if they feel like being up.
When and How to Use Fever-Reducing Medicine
Acetaminophen (Tylenol) can be given to children 2 years and older without a doctor’s guidance. For children under 2, check with your pediatrician before giving it. The standard liquid form contains 160 mg per 5 mL. Dose it based on your child’s weight, not their age, for the most accurate amount. You can repeat a dose every 4 hours as needed, but don’t exceed 5 doses in 24 hours.
Ibuprofen (Motrin, Advil) is an option for children 6 months and older. Like acetaminophen, dosing should be based on weight. It can be given every 6 to 8 hours. Do not give ibuprofen to babies under 6 months old.
You may have heard about alternating between acetaminophen and ibuprofen. Pediatric experts generally advise against this. There’s no evidence that alternating works better than using one medicine alone, and the complicated timing makes it easy to accidentally give too much. Stick with one or the other.
Watch for Signs of Dehydration
Fevers cause children to lose fluids faster than normal, so dehydration is a real concern, especially in younger kids. Three signs to watch for: no wet diapers for three hours or more, no tears when crying, and skin that stays pinched up instead of flattening back right away when you gently squeeze it. If you notice any of these, call your pediatrician.
Red Flags That Need Medical Attention
Call your pediatrician if your child:
- Is under 2 years old and the fever lasts more than 24 hours
- Is 2 years or older and the fever lasts more than 3 days (72 hours)
- Seems listless or confused, won’t make eye contact, or is unusually difficult to wake
- Is vomiting repeatedly or complains of a severe headache, sore throat, or stomachache
- Is extremely irritable in a way that goes beyond normal crankiness
Go to the emergency room if the fever developed after your child was left in a hot car, or if your child has a stiff neck, a rash of small purple or red dots that don’t fade when you press on them, or trouble breathing.
What to Do if Your Child Has a Seizure
Febrile seizures happen in about 2 to 5 percent of children between ages 6 months and 5 years. They look terrifying but are usually not dangerous. During a seizure, your child may shake, stiffen, or lose consciousness for a short time.
If it happens, lay your child on their side on a safe surface. Don’t put anything in their mouth. Don’t try to hold them down. Time the seizure. Most febrile seizures last under two minutes and stop on their own.
If this is your child’s first febrile seizure, take them to the emergency room or call their pediatrician right away afterward, even if they seem fine. The doctor needs to confirm that the seizure was caused by the fever and not something more serious. Call 911 if the seizure lasts longer than 5 minutes or if your child doesn’t seem to recover well afterward. Seizures lasting longer than 15 minutes are considered complex febrile seizures and typically require treatment.
The Bottom Line on Fever Numbers
Parents often worry most about how high the number is, but the temperature alone doesn’t tell you how sick your child is. A child with a 103°F fever who is drinking fluids and playing between naps is generally in better shape than a child with a 101°F fever who is limp and unresponsive. Pay more attention to how your child looks and behaves than to the exact reading on the thermometer. A fever is your child’s immune system doing its job. Your job is to keep them comfortable, hydrated, and watched.