If your baby has a fever, the first thing to do is check their age. A fever in a baby under 3 months old (a rectal temperature of 100.4°F or 38°C or higher) requires immediate medical attention, even if your baby seems fine otherwise. For older babies, most fevers can be safely managed at home with fluids, light clothing, and careful monitoring.
Check Your Baby’s Age First
Age is the single most important factor in deciding what to do. A fever in the first 12 weeks of life can signal a serious infection and needs evaluation in a medical setting right away. Doctors treat any rectal temperature of 100.4°F (38°C) or above in this age group as potentially serious. Your baby will likely need blood work, a urine test, and possibly other tests to rule out bacterial infections. Don’t wait to see if the fever comes down on its own, and don’t give fever-reducing medication before calling your pediatrician.
For babies 3 to 6 months old, call your pediatrician if the temperature reaches 102°F (38.9°C) or if the fever lasts more than a day. For babies older than 6 months, a fever alone is less concerning. Pay more attention to how your baby is acting than to the number on the thermometer.
How to Take an Accurate Temperature
For any baby under 3 years old, a rectal temperature gives the most reliable reading. The American Academy of Pediatrics recommends this method because armpit readings are the least accurate, and ear thermometers aren’t reliable for babies under 3 months (a small, curved ear canal throws off the reading). Forehead thermometers are convenient for a quick check but can also be imprecise in very young infants.
To take a rectal temperature, apply a small amount of petroleum jelly to the tip of a standard digital thermometer and insert it about half an inch. Hold it in place until it beeps. If you’ve taken your baby’s temperature another way and the reading seems off, follow up with a rectal reading to confirm.
Keeping Your Baby Comfortable at Home
Fever is your baby’s immune system doing its job. For babies older than 3 months who are otherwise acting normally, the goal isn’t to eliminate the fever completely. It’s to keep your baby comfortable.
Dress your baby in light, breathable clothing. A common instinct is to bundle a feverish baby in blankets, but this traps heat and can push the temperature higher. A good rule of thumb: dress your baby in one layer more than what you’d wear comfortably in the same room. Keep the room at a normal, comfortable temperature for an adult.
Offer fluids frequently. For babies under 6 months, that means breast milk or formula (not water). For older babies, small sips of water between regular feedings help too. Watch for signs of dehydration: fewer wet diapers than usual, crying without tears, a dry mouth, or a sunken soft spot on the top of the head. These signs mean your baby needs medical attention.
Skip the sponge bath. Tepid sponge baths are a common home remedy, but research shows they cause significant discomfort for feverish children without meaningfully reducing the fever. Sponge-bathed babies may cool slightly faster in the first hour, but after two hours there’s no temperature difference compared to babies who weren’t bathed. Alcohol rubs are even worse and should never be used on a baby’s skin.
When Fever-Reducing Medication Is Appropriate
Acetaminophen (Tylenol) can be given to babies, but for children under 2 years old, you should get dosing guidance from your pediatrician first. The dose is based on your baby’s weight, not age, and getting it right matters.
Ibuprofen (Advil, Motrin) should not be given to babies under 6 months of age. For babies older than 6 months who weigh at least 12 pounds, infant ibuprofen drops are an option, again dosed by weight. Your pediatrician can tell you the exact amount.
Never give aspirin to a baby or child. And don’t alternate between acetaminophen and ibuprofen unless your pediatrician specifically tells you to, because mixing medications increases the risk of dosing errors.
Warning Signs That Need Immediate Care
A fever by itself is rarely dangerous for babies over 3 months, but certain symptoms alongside a fever are red flags. Get medical help right away if your baby:
- Is unusually sleepy or hard to wake up. Some drowsiness with a fever is normal, but a baby who seems floppy, won’t make eye contact, or can’t be roused needs evaluation.
- Is crying inconsolably or crying in a way that sounds different from their normal cry.
- Shows signs of dehydration like fewer wet diapers, no tears, or a sunken soft spot.
- Has trouble breathing, including fast breathing, flaring nostrils, or skin pulling in between the ribs.
- Develops a rash that doesn’t fade when you press on it (small red or purple dots that stay visible under pressure).
- Vomits repeatedly or refuses to eat for several feedings in a row.
What to Do During a Febrile Seizure
About 2 to 5 percent of children between 6 months and 5 years will experience a febrile seizure, a convulsion triggered by a rapid rise in body temperature. It’s terrifying to watch, but most febrile seizures stop on their own within a couple of minutes and don’t cause lasting harm.
If it happens, stay calm and place your baby on their side on a soft, flat surface where they can’t fall. Start timing the seizure. Loosen any tight clothing. Don’t restrain your baby, don’t try to hold their tongue, and don’t put anything in their mouth. Stay close and watch.
Call 911 if the seizure lasts more than five minutes, if your baby has repeated seizures, or if your baby doesn’t seem to recover quickly after the seizure stops. Even if the seizure is brief and your baby bounces back, call your pediatrician afterward so they can evaluate what caused it.