For most fevers in adults, acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) will bring your temperature down effectively. Both work by reducing the chemical signals in your brain that push your body’s thermostat higher during illness. Which one you reach for depends on your health history, your age, and how long you need relief to last.
Acetaminophen vs. Ibuprofen for Adults
Acetaminophen and ibuprofen are the two go-to options, and they work differently enough that the choice matters. Acetaminophen acts primarily in the brain to lower fever and relieve pain. Ibuprofen does the same but also reduces inflammation throughout the body, making it a better fit when your fever comes with body aches, sore throat, or swollen sinuses.
For ibuprofen, the standard adult dose is 200 to 400 mg every four to six hours as needed. The FDA-approved maximum is 3,200 mg per day under medical supervision, but for over-the-counter use, most labels recommend staying well below that. Acetaminophen is typically taken as 500 to 1,000 mg every four to six hours, with a hard ceiling of 4,000 mg in 24 hours for adults and children 12 and older. Going above that threshold risks serious liver damage, especially if you drink alcohol regularly or take other products that contain acetaminophen (many cold and flu formulas do, so check the label).
A third option is naproxen (Aleve). It lasts longer than ibuprofen, so you take it less often: 440 mg as a first dose, then 220 mg every 8 to 12 hours. That longer window can be helpful if your fever keeps creeping back overnight.
Who Should Avoid NSAIDs
Ibuprofen and naproxen both belong to a class of drugs called NSAIDs, and they carry risks that acetaminophen does not. If you have a history of stomach ulcers, intestinal bleeding, or chronic heartburn, NSAIDs can make those problems worse. People with heart disease, kidney disease, or liver disease are also at higher risk for complications. Adults over 65 face elevated risk across all of these categories.
NSAIDs can raise the risk of heart attack, stroke, and serious gastrointestinal bleeding, particularly with prolonged use. Don’t use an over-the-counter NSAID for more than 10 days without talking to a doctor. If you’re pregnant, trying to become pregnant, or breastfeeding, avoid NSAIDs unless your doctor specifically approves them. For people in any of these groups, acetaminophen is generally the safer choice for fever.
Fever Medication for Children
Children’s fever treatment follows different rules. Acetaminophen is available as a liquid syrup (160 mg per 5 mL) and should be dosed by weight, not age. For children under 12, it can be given every four hours, with no more than five doses in 24 hours. Children under 2 should not receive acetaminophen without a doctor’s guidance. Extra-strength 500 mg products are not appropriate for children under 12, and extended-release 650 mg formulations should not be given to anyone under 18.
Ibuprofen is generally safe for children 6 months and older, also dosed by weight. The most important rule for children, however, is this: never give aspirin to a child or teenager. Aspirin has been linked to Reye’s syndrome, a rare but potentially fatal condition that causes swelling in the liver and brain, particularly in children recovering from the flu or chickenpox.
Alternating Medications for Stubborn Fevers
You may have heard that alternating acetaminophen and ibuprofen works better than either one alone. Research from the American Academy of Pediatrics shows that dual therapy (either alternating or combining the two) does produce a higher percentage of fever-free children at the four- and six-hour marks compared to acetaminophen alone. No increase in side effects was observed in the short term.
That said, the AAP recommends starting with a single medication and reassessing comfort and hydration before adding a second. The alternating schedule is more complicated, since acetaminophen can be given every four to six hours while ibuprofen is given every six to eight, and the mismatch increases the chance of dosing errors. Long-term safety data on repeated alternating doses during a multi-day illness is still limited. If one medication on its own is keeping your child comfortable and hydrated, there’s no need to complicate things.
Cooling Methods That Actually Help
Tepid sponge baths, using lukewarm (not cold) water, are a traditional remedy that does have some evidence behind them. A clinical study of children aged 6 months to 12 years found that tepid sponging combined with an antipyretic drug reduced fever significantly more than medication alone, starting at the 30-minute mark and continuing through two hours. At the 15-minute mark, there was no measurable difference, so the sponge bath needs a little time to work alongside the medication.
Cold water or ice baths are not recommended. They can cause shivering, which actually raises your core temperature. Lukewarm water works because it pulls heat away from the skin gradually without triggering that rebound. Lightweight clothing and a light blanket, rather than bundling up, also help your body shed heat naturally.
Staying Hydrated During a Fever
Fever increases fluid loss through sweating, and if vomiting or diarrhea is part of your illness, you’re losing electrolytes on top of water. That combination can lead to dehydration faster than you might expect. Water is fine for mild fevers, but if you’re sweating heavily or have GI symptoms, a drink with electrolytes (sports drinks, oral rehydration solutions, or diluted juice with a pinch of salt) helps replace what you’re losing. Small, frequent sips work better than trying to drink a large amount at once, especially if your stomach is unsettled.
When a Fever Needs Medical Attention
A fever of 100.4°F (38°C) or higher is the standard threshold for adults, whether measured orally, rectally, or with an ear thermometer. Armpit readings run a little lower, so 99°F (37.2°C) in the armpit is considered a fever. Most fevers in that range are uncomfortable but not dangerous.
Adults with fevers of 103°F (39.4°C) or higher typically look and act noticeably sick and should seek medical care, especially if accompanied by trouble breathing, chest pain, a bad headache, or a stiff neck. Confusion and repeated vomiting or diarrhea are also red flags at any temperature.
For infants under 3 months old, any fever of 100.4°F or higher requires immediate medical attention, regardless of how the baby appears. For older children, watch for signs of dehydration, persistent fussiness that doesn’t improve after medication, or any behavior that strikes you as unusual. A fever that doesn’t respond to medication at all, or one that persists beyond three days, warrants a call to your doctor.