The most effective way to keep a fever down is a combination of over-the-counter fever reducers, steady fluid intake, and a cool environment. Most fevers in older children and adults are not dangerous on their own, and these basic measures will bring your temperature down enough to rest comfortably while your body fights the underlying infection.
What Counts as a Fever
The number that qualifies 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 counts. An armpit reading of 99°F (37.2°C) or higher qualifies, though armpit readings tend to be less precise.
For infants under 3 months old, any temperature at or above 100.4°F is treated as a medical urgency regardless of how the baby looks or acts. Babies this young need same-day evaluation, not home management. This is especially critical for newborns under 3 weeks, who are typically hospitalized for testing and observation whenever a true fever is confirmed.
Fever-Reducing Medication
Acetaminophen (Tylenol) and ibuprofen (Advil, Motrin) are the two standard options. Both lower fever effectively, but they work differently and follow different schedules.
Acetaminophen can be given every 4 to 6 hours, up to 5 times in 24 hours. It’s safe for most people, including children 8 weeks and older. Ibuprofen can be given every 6 to 8 hours, up to 4 times in 24 hours, but should not be given to infants under 6 months old. For children, dosing is based on weight rather than age, so check the packaging carefully.
Some parents alternate between the two medications to keep a fever suppressed more continuously. This can work, but it also increases the risk of accidentally giving too much of one or both. If you go this route, write down every dose and the time you gave it.
Never Give Aspirin to Children
Aspirin is linked to Reye’s syndrome, a rare but serious condition affecting the brain and liver, in children and teenagers who have viral infections like the flu or chickenpox. This applies to plain aspirin and any product containing it. Aspirin sometimes shows up in unexpected places like Alka-Seltzer, so always read labels before giving any medication to a child or teen.
Stay Ahead of Dehydration
A fever increases fluid loss through sweating and faster breathing. Replacing those fluids is just as important as taking medication. Offer water, broth, or sports drinks throughout the day. If the person with a fever isn’t eating much, fluids become even more critical.
Avoid alcohol, coffee, tea, and caffeinated sodas, all of which can increase fluid loss. If someone is too weak to drink from a cup, try a squeeze bottle, a straw, or ice chips and frozen popsicles. For babies, continue breastfeeding or formula feeding as usual. Babies get all the hydration they need from breast milk or formula. If a baby refuses to nurse or take a bottle, that’s a reason to call your pediatrician, who may recommend an oral rehydration solution like Pedialyte.
Older adults and people with kidney problems should check with their doctor about how much fluid is safe to drink during illness, since some conditions require fluid limits even when sick.
Cool the Environment, Not the Body
Keep the room at a comfortable temperature and dress in lightweight clothing. It’s tempting to pile on blankets when you feel chilled, but heavy layers trap heat and can actually push your temperature higher. A single light blanket is fine if you’re uncomfortable.
A lukewarm sponge bath can help bring a fever down when medication alone isn’t enough. Use water between 90°F and 95°F (32°C to 35°C). Focus on the forehead, neck, and armpits. Do not use cold water, ice, or rubbing alcohol. Cold temperatures cause shivering, which generates more body heat and works against you. Rubbing alcohol can be absorbed through the skin and is toxic, especially for children.
Rest and Sleep
Fever is your immune system working harder, and that takes energy. Pushing through normal activities while feverish slows recovery and keeps your temperature elevated. Sleep is the single best thing you can do alongside medication and fluids. If you can, clear your schedule and stay in bed.
For children, quiet activities like reading or watching a show are fine, but avoid physical play until the fever has been gone for at least a day. Children with fevers often cycle between feeling miserable and feeling almost normal, especially right after medication kicks in. The temporary improvement doesn’t mean they’re ready to run around.
How Long a Fever Typically Lasts
Most viral fevers last 2 to 3 days, though some infections (like the flu) can cause fevers lasting 5 days or more. The fever often peaks in the late afternoon and evening and drops lower in the morning, so don’t be alarmed by a pattern that seems to improve and then worsen each day.
A fever that climbs above 103°F (39.4°C) in an adult despite medication, or one that lingers beyond 3 days without a clear cause, is worth a call to your doctor. For children between 3 months and 2 years old, a fever lasting more than a day warrants medical advice even if the child seems generally well.
Warning Signs That Need Immediate Attention
Most fevers resolve on their own, but certain symptoms alongside a fever signal something more serious. Seek immediate medical care if a fever comes with any of the following:
- Stiff neck or pain when bending the head forward
- Seizure or convulsion
- Confusion, altered speech, or strange behavior
- Difficulty breathing or chest pain
- Persistent vomiting that prevents keeping fluids down
- Rash, especially one that doesn’t fade when you press on it
- Unusual sensitivity to bright light
- Swelling or inflammation in any part of the body
For infants under 3 months, the threshold is much lower. Any true fever (100.4°F or above) in this age group needs prompt medical evaluation, even if the baby appears well and has no other symptoms.