The safest ways to reduce a baby’s fever include keeping your baby lightly dressed, offering plenty of fluids, giving a lukewarm sponge bath, and using age-appropriate fever-reducing medication when needed. A rectal temperature of 100.4°F (38°C) or higher counts as a fever in infants. Before you start treating it, though, it helps to understand that fever itself isn’t the enemy. It’s your baby’s immune system actively fighting off infection, and a mild fever in an otherwise alert, feeding baby doesn’t always need to be brought down.
Why Babies Get Fevers
Fever is one of the body’s most effective defense tools. When your baby’s temperature rises by even 1 to 4°C, immune cells become more active, move faster toward infection sites, and communicate more efficiently with each other. Research published in Nature Reviews Immunology found that this temperature increase is associated with improved survival and faster resolution of many infections. So a low-grade fever in a baby who is still drinking, making wet diapers, and responding to you normally may not need any treatment at all.
That said, fever can make babies uncomfortable, disrupt sleep, and speed up fluid loss. The goal of treatment isn’t necessarily to get the number back to 98.6°F. It’s to help your baby feel better and stay hydrated while their body does its job.
How to Take an Accurate Temperature
For babies younger than 3 months, a rectal thermometer is the most accurate method and the one pediatricians rely on. Forehead (temporal) thermometers can work as a first pass for babies 3 months and older, but if your baby seems sick, a rectal reading gives you the most reliable number. Ear thermometers aren’t recommended until after 6 months, and armpit readings, while convenient, are the least precise option for young infants.
To take a rectal temperature, apply a small amount of petroleum jelly to the tip of a digital thermometer and insert it about half an inch. Hold it in place until it beeps. If the reading is 100.4°F or above, your baby has a fever.
Cooling Techniques That Work
Dress Lightly
Your instinct might be to bundle a feverish baby up, but extra layers trap heat and can push the temperature higher. One light layer of clothing is enough. Keep the room between 60°F and 68°F (16 to 20°C) for sleeping, which is comfortable and safe even for sick babies. The NHS notes that most babies who are unwell or feverish do not need extra clothes, even in winter.
Give a Lukewarm Sponge Bath
A sponge bath can bring mild relief, but the water temperature matters. Use lukewarm water between 90°F and 95°F (32°C to 35°C), not cold water. Cold water, ice, or rubbing alcohol can cause your baby’s temperature to drop too quickly, triggering shivering, which actually raises body temperature. Sponge your baby gently for 20 to 30 minutes. If your baby starts shivering at any point, stop immediately and pat them dry.
Push Fluids
Fever increases fluid loss, so keeping your baby hydrated is one of the most important things you can do. For babies under 12 months, breast milk and formula are the best options. Don’t stop breastfeeding during a fever. If your baby is vomiting or showing signs of dehydration (fewer wet diapers, dry mouth, no tears when crying), you can offer an oral rehydration solution like Pedialyte in small, frequent sips.
Start with about 1 teaspoon (5 mL) every 5 to 10 minutes if your baby is having trouble keeping fluids down. For a rough hourly target, babies weighing 7 to 10 pounds need at least 2 ounces per hour, babies 11 to 15 pounds need about 2.5 ounces, and babies 16 to 20 pounds need at least 3.5 ounces. These minimums go up when fever, vomiting, or diarrhea are present. Avoid fruit juice, sugary drinks, and teas.
When Medication Is Appropriate
Acetaminophen (Tylenol) is the go-to fever reducer for young babies, but it should not be given to infants under 12 weeks of age unless directed by a pediatrician. Dosing is based on weight, not age. For infant liquid (160 mg per 5 mL), the general ranges are:
- 6 to 11 pounds: 1.25 mL
- 12 to 17 pounds: 2.5 mL
- 18 to 23 pounds: 3.75 mL
- 24 to 35 pounds: 5 mL
You can repeat a dose every 4 to 6 hours as needed, but no more than 5 times in 24 hours. Always use the measuring syringe that comes with the product rather than a kitchen spoon.
Ibuprofen (Motrin, Advil) is an option for babies 6 months and older. The dose depends on both weight and how high the fever is. For fevers under 102.5°F, the typical dose is lower than for higher fevers. Your pediatrician can give you the exact amount for your baby’s weight.
Alternating Medications
You may have heard about alternating acetaminophen and ibuprofen to keep fever down more consistently. The American Academy of Pediatrics advises against doing this routinely. The concern is that juggling two medications increases the risk of dosing errors, and there’s a theoretical risk of liver and kidney stress from the combination. Case reports have documented reversible kidney problems in children receiving both medications at standard doses. If a single medication isn’t providing enough relief, talk to your pediatrician before adding a second one. A short alternating course may be reasonable in some situations, but it shouldn’t be your default approach.
Warning Signs That Need Medical Attention
Any fever of 100.4°F or higher in a baby under 3 months old warrants an immediate call to your pediatrician or a trip to the emergency room, even if your baby looks fine. At that age, fever can signal a serious bacterial infection that’s harder to detect by appearance alone.
For babies 3 to 6 months old, a temperature up to 101°F isn’t automatically an emergency, but call your pediatrician if your baby seems unusually irritable, sleepy, or uncomfortable, or if the temperature goes higher. For babies 6 to 24 months, a fever above 101°F that lasts more than a day without other symptoms also deserves a call.
Regardless of age, seek immediate care if your baby shows any of these signs alongside a fever: extreme sleepiness or difficulty waking, a weak or unusual-sounding cry that won’t stop, a rash with flat purple or red spots that don’t fade when you press on them, difficulty breathing, refusal to drink for several hours, or fewer than three wet diapers in 24 hours. A non-blanching rash (spots that stay dark when you press a glass against them) is particularly urgent and can indicate serious infections like meningitis.
What You Can Skip
A few old remedies persist that are either ineffective or dangerous. Never use rubbing alcohol on your baby’s skin to cool a fever. It absorbs through the skin and can cause alcohol poisoning. Ice baths and cold water are also harmful because they cause rapid surface cooling, trigger intense shivering, and can actually raise core temperature. Starving a fever has no basis in medicine either. Babies need more fluids when feverish, not fewer calories.
You also don’t need to wake a sleeping baby to treat a fever unless their pediatrician has specifically told you to. Sleep is restorative, and if your baby is resting comfortably, that’s a good sign. Check on them periodically, but let them rest.