A fever is a temperature of 100.4°F (38°C) or higher, and in most cases, the best thing to do is rest, stay hydrated, and let your body do its job. Fever is not an illness itself. It’s your immune system’s way of fighting off an infection, and it usually resolves on its own within a few days. That said, knowing how to stay comfortable, when to use medication, and which warning signs require medical attention can make a real difference.
Why Your Body Runs a Fever
Fever exists for a reason. When your body temperature rises, your immune cells become significantly more active. Research from the National Institutes of Health found that at fever temperature (around 102.2°F), T cells, a key part of your immune defense, multiply faster and release more of the signaling molecules that coordinate your body’s response to infection. At the same time, the cells that normally dial down immune activity become less effective, giving your body a stronger inflammatory response to fight off whatever is making you sick.
This is why many doctors don’t recommend aggressively treating a mild fever if you’re otherwise feeling okay. A low-grade fever in a healthy adult is your body working as designed. The goal of treatment isn’t necessarily to eliminate the fever entirely, but to keep you comfortable enough to rest and recover.
Stay Hydrated
Your body loses water faster when you have a fever. You’re sweating more, breathing faster, and your metabolism is running at a higher rate. The CDC notes that your body needs more water whenever you’re running a fever, and that dehydration during illness can cause unclear thinking, mood changes, and overheating, all of which make you feel worse than the fever alone.
Water is the simplest option, but broth, diluted juice, and oral rehydration solutions also work well. Sip steadily throughout the day rather than trying to drink large amounts at once, especially if your stomach is unsettled. If your urine is dark yellow or you’re urinating very infrequently, you need more fluids.
When to Use Fever-Reducing Medication
Over-the-counter options like acetaminophen and ibuprofen can bring your temperature down and relieve the aches, chills, and headache that often come with a fever. For adults and children 12 and older, either medication is generally appropriate. Follow the dosing instructions on the package, and don’t exceed the recommended daily maximum. Acetaminophen and ibuprofen work differently in the body, so they can be alternated if one alone isn’t providing enough relief, but be careful to track timing so you don’t accidentally double up.
You don’t necessarily need medication for every fever. If your temperature is mildly elevated and you feel tolerable, rest and fluids may be enough. Medication becomes more useful when the fever is making it hard to sleep, eat, or stay hydrated.
Fever Medication for Children
Children’s acetaminophen is typically available as a liquid (160 mg per 5 mL), and dosing should be based on your child’s weight rather than age whenever possible. Children under 12 can take a dose every 4 hours, with no more than 5 doses in 24 hours. Children under 2 should not receive acetaminophen without guidance from a pediatrician. The same applies to ibuprofen, which is not recommended for infants under 6 months.
Simple Comfort Measures
Beyond medication, a few practical steps can help you feel better while your body fights the infection:
- Dress lightly. Bundling up in heavy blankets can trap heat and push your temperature higher. Lightweight clothing and a single sheet or light blanket are usually enough.
- Keep the room cool. A slightly cool, well-ventilated room helps your body release excess heat.
- Try a lukewarm sponge bath. If your fever is high and you’re very uncomfortable, sponging with lukewarm water (90°F to 95°F) for 20 to 30 minutes can help bring your temperature down. Stop if you start shivering, because shivering actually raises your core temperature. Never use cold water, ice, or rubbing alcohol, as these cool the body too quickly and can be dangerous.
- Rest. Your immune system works best when your body isn’t spending energy on other things. Sleep as much as you can.
How Long a Fever Typically Lasts
Most fevers caused by common viral infections (colds, flu, stomach bugs) last 2 to 3 days, with some lingering up to 5 days. The fever often peaks in the late afternoon or evening and drops overnight, which can create a frustrating pattern of feeling better in the morning and worse by nightfall. This is normal. As long as the overall trend is improving and no red-flag symptoms develop, your body is likely handling the infection on its own.
Warning Signs That Need Medical Attention
Most fevers are harmless, but certain symptoms alongside a fever signal something more serious. Seek immediate medical attention if a fever comes with any of the following:
- Stiff neck with pain when bending your head forward
- Mental confusion, strange behavior, or altered speech
- Difficulty breathing or chest pain
- Persistent vomiting
- Severe headache
- New rash
- Unusual sensitivity to bright light
- Pain when urinating
- Seizures or convulsions
These can indicate conditions like meningitis, sepsis, or other infections that need treatment beyond what your immune system can handle alone.
Fever in Babies and Young Children
The rules change significantly for infants. Any baby under 3 months old with a rectal temperature of 100.4°F or higher needs medical evaluation right away, even if the baby looks fine. At this age, a fever can be the only sign of a serious bacterial infection, and doctors follow specific protocols based on the infant’s exact age to determine what testing is needed. The American Academy of Pediatrics has detailed guidelines for evaluating febrile infants as young as 8 days old, which may include blood work and urine tests. Don’t wait to see if the fever resolves on its own in a newborn.
For older children, the fever itself matters less than how the child is acting. A child with a 103°F fever who is still drinking fluids, making eye contact, and responding to you is generally in less danger than a child with a 101°F fever who is listless, confused, or unresponsive. Call your pediatrician if your child is vomiting repeatedly, has a severe headache or stomachache, or seems unusually irritable or lethargic. If a child has a fever-related seizure lasting more than five minutes, call 911.
What to Avoid
A few common instincts during a fever actually make things worse. Piling on blankets to “sweat it out” can dangerously elevate your temperature. Taking a cold bath or applying ice packs causes shivering, which raises your core temperature. Rubbing alcohol on the skin was once a popular home remedy but can be absorbed through the skin and is no longer recommended.
Aspirin should never be given to children or teenagers with a fever, as it’s linked to a rare but serious condition called Reye’s syndrome. Stick with acetaminophen or ibuprofen for younger patients, dosed by weight using the product’s guidelines.