The fastest way to bring a fever down is to take an over-the-counter fever reducer like acetaminophen (Tylenol) or ibuprofen (Advil, Motrin), stay well hydrated, and rest. Most fevers in otherwise healthy people resolve on their own within a few days, but these steps can make you or your child significantly more comfortable while the body fights off infection.
Why Your Body Runs a Fever
A fever isn’t the illness itself. It’s your immune system’s response. When your body detects an infection, it deliberately raises its internal thermostat, which is controlled by a small region deep in the brain. This higher temperature helps your white blood cells work more efficiently and makes it harder for many viruses and bacteria to reproduce. That’s why most experts don’t recommend aggressively treating a low-grade fever unless it’s causing real discomfort. The goal of fever reduction is to help you feel better, not necessarily to eliminate the fever entirely.
Over-the-Counter Fever Reducers
Acetaminophen and ibuprofen are the two main options. Both lower fever effectively, but they work differently and have different timing.
Acetaminophen
Acetaminophen can be given every 4 to 6 hours as needed, with no more than 5 doses in 24 hours. For children, the correct dose is based on weight, not age. Do not give acetaminophen to infants under 8 weeks old. Adults typically take 500 to 1,000 mg per dose, staying under 3,000 mg per day (or 4,000 mg if directed by a doctor). Acetaminophen is gentler on the stomach than ibuprofen, which makes it a good first choice for people who are nauseous or have a sensitive stomach.
Ibuprofen
Ibuprofen can be given every 6 to 8 hours, with no more than 4 doses in 24 hours. It reduces both fever and inflammation, so it tends to be especially effective when a fever comes with body aches or sore throat. For children, dosing is also weight-based. Do not give ibuprofen to infants under 6 months old unless specifically told to by a doctor. Children over 95 pounds can take 500 to 650 mg per dose, not exceeding 4,000 mg in 24 hours.
Aspirin: Not for Children
Never give aspirin to children or teenagers. Aspirin use during a viral illness like the flu or chickenpox has been linked to Reye’s syndrome, a rare but serious condition that causes swelling in the liver and brain. This applies to plain aspirin and any product containing salicylate or acetylsalicylic acid. Some children with specific chronic conditions like Kawasaki disease may take aspirin under medical supervision, but that’s the only exception.
Hydration Matters More Than You Think
Fever increases your body’s fluid needs by roughly 12% for every degree Celsius above normal. That adds up quickly. A fever of 39.5°C (about 103°F) means your body is burning through fluids 24% faster than usual, through sweating, faster breathing, and increased metabolic activity. Dehydration makes you feel worse and can make a fever harder to break.
Water is fine, but if you’re not eating much, drinks with some electrolytes and sugar (like diluted juice, broth, or an oral rehydration solution) help your body absorb fluid more efficiently. For young children, offer small sips frequently rather than large amounts at once. Signs of dehydration to watch for include dark urine, dry lips, no tears when crying (in children), and dizziness when standing.
What About Cold Baths and Sponging?
Tepid sponge baths are a common home remedy, but the evidence is underwhelming. In a study of febrile children aged 5 to 68 months, those who received a 15-minute tepid sponge bath alongside acetaminophen cooled slightly faster in the first hour compared to children who took acetaminophen alone. By the two-hour mark, there was no meaningful temperature difference between the groups. More importantly, the children who were sponge-bathed had significantly higher discomfort scores.
If you want to use external cooling, a lukewarm (not cold) washcloth on the forehead or neck is reasonable for comfort. Avoid ice baths, rubbing alcohol on the skin, or very cold water. These can trigger shivering, which actually raises your core temperature further as your muscles contract to generate heat.
Other Steps That Help
Dress in light, breathable clothing. Layering heavy blankets on top of a fever traps heat and can push the temperature higher. A single light sheet or blanket is enough if you have chills. Keep the room at a comfortable temperature rather than cranking up the heat.
Rest is genuinely important. Your immune system is energy-intensive, and physical activity generates additional body heat. Lying down in a cool, quiet room lets your body direct resources toward fighting the infection. Sleep as much as your body wants.
Getting an Accurate Temperature Reading
The number on your thermometer depends on where you measure. Rectal and ear readings run about 0.5 to 1°F (0.3 to 0.6°C) higher than an oral reading. Armpit and forehead readings run about 0.5 to 1°F lower than oral. So a forehead reading of 99.5°F may actually correspond to an oral temperature closer to 100°F.
For infants, rectal thermometers remain the most accurate method. For older children and adults, oral or ear thermometers are reliable enough for home use. Forehead scanners are convenient but tend to be the least precise, especially if the person has been sweating or in a very warm or cold room.
Fevers in Infants Need Immediate Attention
The rules change significantly for babies. The American Academy of Pediatrics treats any fever of 100.4°F (38°C) or higher in infants 8 to 60 days old as a situation requiring medical evaluation, even if the baby looks well. For babies under 8 weeks, a fever at this threshold warrants an emergency visit. Young infants have immature immune systems, and a fever can be the only early sign of a serious bacterial infection.
Signs of a more dangerous illness in babies include constant crying that can’t be soothed, extreme sleepiness or difficulty waking, poor feeding, vomiting, a bulging soft spot on the head, or stiffness in the body and neck.
Red Flags at Any Age
Most fevers are caused by common viral infections and resolve within 3 to 5 days. But certain symptoms alongside a fever signal something more serious, like meningitis or sepsis, and require emergency care:
- Stiff neck combined with headache and fever
- Confusion or difficulty concentrating
- Seizures
- A rash that doesn’t fade when you press on it (especially purplish spots)
- Sensitivity to light
- Persistent vomiting with severe headache
- Trouble breathing or chest pain
A fever above 103°F (39.4°C) in adults that doesn’t respond to medication, or any fever lasting more than three days, also warrants a call to your doctor. In children, a fever that keeps returning after a brief improvement or one accompanied by listlessness and refusal to drink fluids should be evaluated promptly.