Most fevers don’t need aggressive treatment. A fever is your immune system’s deliberate response to infection, raising your body’s internal thermostat to create an environment that’s harder for viruses and bacteria to thrive in. For adults, a fever under 103°F (39.4°C) that isn’t paired with worrying symptoms can typically be managed at home with a combination of over-the-counter medication, fluids, rest, and simple cooling techniques.
Why Your Body Runs a Fever
Your brain has a temperature control center that works like a thermostat. When you get sick, your immune system releases chemical signals called pyrogens that change how this thermostat operates. These signals suppress the neurons that normally keep you cool and activate the ones responsible for generating heat. The result: your body “resets” to a higher target temperature, which is why you feel chilled and start shivering even though your skin is already warm. That shivering is your muscles generating heat to reach the new, higher set point.
This process is intentional. A higher body temperature speeds up immune cell activity and makes it harder for many pathogens to reproduce. That’s why mild fevers don’t always need to be brought down. The goal of fever reduction is comfort, not eliminating the fever entirely.
Over-the-Counter Fever Reducers
Acetaminophen (Tylenol) and ibuprofen (Advil, Motrin) are the two standard options for lowering a fever. Both work well, but they differ in a few practical ways. Ibuprofen also reduces inflammation, which can help if your fever comes with body aches or a sore throat. You can take ibuprofen every 6 to 8 hours as needed, with a standard adult dose of 400 mg. Acetaminophen can be taken every 4 to 6 hours.
For children, dosing is based on weight, not age. If you don’t know your child’s weight, age can serve as a rough guide, but weight is more accurate. Ibuprofen should not be given to babies younger than 6 months old unless a pediatrician specifically recommends it, as it hasn’t been established as safe in that age group.
One critical rule: never give aspirin to children or teenagers with a fever. Aspirin has been linked to Reye’s syndrome, a rare but serious condition that causes swelling in the liver and brain, particularly in kids recovering from the flu or chickenpox. The only exception is children on long-term aspirin therapy for specific chronic conditions like Kawasaki disease, prescribed and monitored by their doctor.
Stay Hydrated
Fever increases the rate at which your body loses water through the skin. For every degree Celsius above 38°C (100.4°F), your fluid losses through the skin rise by roughly 10%. That adds up quickly, especially if the fever lasts more than a day or is accompanied by sweating, vomiting, or diarrhea.
Water is fine. So are diluted juice, broth, oral rehydration solutions, and popsicles for kids who resist drinking. The goal is steady sipping rather than forcing large amounts at once. If your urine is dark yellow or you’re urinating much less than usual, you need more fluids.
Cooling Techniques That Work
A lukewarm sponge bath can help bring a fever down when used alongside medication. The key is water temperature: use water between 90°F and 95°F (32°C to 35°C). That feels barely warm to the touch. Sponge the skin gently for 20 to 30 minutes, focusing on the forehead, neck, and armpits. Stop immediately if shivering starts, because shivering actually generates more heat and can push the temperature back up.
Do not use cold water, ice baths, or rubbing alcohol. These cool the skin surface too rapidly, triggering intense shivering and potentially causing a dangerous drop in temperature. Rubbing alcohol can also be absorbed through the skin and is toxic, especially for children.
Beyond sponge baths, simpler measures help too. Dress in lightweight clothing rather than bundling up. Keep the room comfortably cool. Use a single light blanket if you feel chilled.
Rest More Than You Think You Need To
When you’re feverish, your body is diverting significant energy toward immune function. Trying to power through your normal routine forces your system to split resources between fighting the infection and fueling physical or mental activity. Research shows this trade-off can stretch a three- to four-day illness considerably longer and raise the risk of complications like secondary infections.
Practical rest means avoiding strenuous exercise, staying home from work or school, and sleeping as much as your body wants. Light activity around the house is generally fine if you feel up to it, but this isn’t the time for a workout or a packed schedule.
Fevers That Need Medical Attention
Infants
Any baby younger than 3 months with a rectal temperature of 100.4°F (38°C) or higher needs immediate medical evaluation. This isn’t a “wait and see” situation. More than 10% of febrile infants turn out to have a urinary tract infection, and while more serious infections like meningitis are rare (fewer than 0.05% of cases), the stakes are high enough that early evaluation matters.
For babies 3 to 6 months old, a rectal temperature above 102°F (38.9°C) warrants a call to the pediatrician, as does a lower fever paired with unusual irritability, sluggishness, or poor feeding. Between 7 and 24 months, a temperature above 102°F that persists beyond 24 hours without other obvious symptoms also needs a professional look.
Children
Beyond the temperature itself, watch for these signs in kids of any age: listlessness or confusion, poor eye contact, repeated vomiting, severe headache, or significant discomfort that doesn’t improve with fever reducers. A fever lasting longer than three days deserves a call to the pediatrician regardless of the number on the thermometer. Any seizure associated with fever warrants emergency care. Call 911 if a seizure lasts more than five minutes or if the child doesn’t recover quickly.
Adults
Call your healthcare provider if your temperature reaches 103°F (39.4°C) or higher. Seek emergency care if a fever comes with any of the following: severe headache, a new rash, sensitivity to bright light, a stiff neck with pain when bending forward, mental confusion or altered speech, persistent vomiting, difficulty breathing or chest pain, abdominal pain, pain during urination, or seizures. These combinations can signal meningitis, sepsis, or other conditions where hours matter.