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 dress in light clothing. Most fevers resolve on their own within a few days, but knowing what works, what doesn’t, and when to act makes the process safer and more comfortable.
Why Your Body Raises Its Temperature
Fever isn’t a malfunction. When your immune system detects a pathogen, immune cells release signaling molecules that travel to the brain’s temperature control center. That center then raises your body’s internal thermostat, triggering the shivering, heat production, and reduced heat loss that push your temperature up. Your body is actively working to reach this new, higher set point.
This process has real benefits. Higher body temperature pushes many pathogens out of their ideal growth range, which is why fungal infections struggle to take hold in mammals at all. Fever also improves the movement of infection-fighting white blood cells throughout the body and enhances their ability to attack invaders. Historically, induced fevers were even used to treat syphilis and showed effectiveness against poliovirus. So a mild fever is your immune system doing its job. The goal isn’t always to eliminate the fever entirely, but to keep yourself comfortable and safe while your body fights the infection.
Fever-Reducing Medication
Acetaminophen and ibuprofen are the two main options. Both work, but they aren’t identical. In studies comparing the two for children under two, ibuprofen lowered temperatures about 0.4°C (0.7°F) more than acetaminophen within four hours. Children given ibuprofen were also roughly twice as likely to be fever-free between 4 and 24 hours after dosing. For adults, both are effective, and the choice often comes down to which one you tolerate better.
Acetaminophen can be taken every 4 to 6 hours, up to 5 times in 24 hours. Ibuprofen is taken every 6 to 8 hours, up to 4 times in 24 hours. For children, dosing should always be based on weight, not age. Adults and children over 12 should stay under 4,000 milligrams of acetaminophen and 1,200 milligrams of ibuprofen per day. Exceeding those limits can cause liver damage (acetaminophen) or kidney damage (ibuprofen).
Never give aspirin to children or teenagers with a fever, as it’s linked to a rare but serious condition called Reye’s syndrome.
Alternating the Two Medications
If one medication alone isn’t bringing enough relief, you can alternate between acetaminophen and ibuprofen. The key is not to take both at the same time. Take one first, then switch to the other four to six hours later, continuing to alternate every three to four hours. This approach has been shown to provide better symptom control than either medication alone. If you find yourself alternating for more than three days, it’s worth checking in with a healthcare provider. People with liver, kidney, digestive, or bleeding disorders should be especially cautious with these medications.
Stay Hydrated
Fever increases the amount of water your body loses through the skin. For every degree Celsius above 38°C (100.4°F), your fluid loss through the skin rises by about 10%. That adds up quickly with a high or prolonged fever, and dehydration will make you feel significantly worse.
Water is the simplest option, but broth, diluted juice, electrolyte drinks, and popsicles all count. Sip consistently throughout the day rather than trying to drink large amounts at once, especially if nausea is an issue. For young children, watch for signs of dehydration: fewer wet diapers, dry lips, no tears when crying, or unusual drowsiness.
Cooling Methods That Actually Help
Light clothing and a light blanket are the right approach. Bundling up in heavy layers traps heat and can push your temperature higher. If you’re experiencing chills, a light blanket is fine until the shivering passes, but avoid piling on covers.
A lukewarm sponge bath can help if medication hasn’t brought enough relief after about 30 minutes. Use water between 32°C and 35°C (90°F to 95°F), and sponge for 20 to 30 minutes. The important word is lukewarm. Cold water, ice baths, and rubbing alcohol are all counterproductive. They cause the body to shiver, which actually generates more heat and raises your core temperature. If a sponge bath causes shivering or distress, stop.
Rest matters too. Physical activity generates heat, and your body is already diverting significant energy toward fighting infection. Lying down in a comfortably cool room gives your body the best conditions to recover.
Fever in Babies and Young Children
The rules change significantly for infants. Any baby under 3 months old (90 days) with a rectal or axillary temperature above 38°C (100.4°F) needs medical evaluation, even if the baby looks well. At that age, a fever can signal a serious infection that isn’t obvious from the outside, and waiting to see how things develop is not safe.
For older babies and toddlers, the number on the thermometer matters less than how the child is behaving. A child with a 102°F fever who is drinking fluids, somewhat playful, and making eye contact is generally less concerning than a child with a 101°F fever who is limp, inconsolable, or refusing to drink. Dose fever-reducing medication by weight, not age, and never give ibuprofen to a baby under 6 months old.
When a Fever Needs Medical Attention
Most fevers in otherwise healthy adults and older children are uncomfortable but not dangerous. However, certain combinations of symptoms signal something more serious. Call your doctor if your temperature reaches 104°F (40°C) or higher. Seek immediate medical help if a fever comes with any of the following:
- Seizure or loss of consciousness
- Confusion or difficulty staying alert
- Stiff neck
- Trouble breathing
- Severe pain anywhere in the body
- Swelling or inflammation in any body part
- Painful urination or foul-smelling urine
A fever that lasts more than three days without improvement, or one that goes away and then returns, also warrants a call to your doctor. For people with weakened immune systems, whether from chemotherapy, organ transplant, HIV, or other conditions, a lower threshold for seeking care is appropriate since fever may be the only early sign of a serious infection.