For most adults with fever and chills, acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) will bring your temperature down and ease discomfort within one to two hours. Both are available over the counter, and both work well, though they differ in how quickly and how much they reduce a fever. Choosing between them depends on your age, health conditions, and how you’re feeling.
Why Fever and Chills Happen Together
Chills aren’t a separate problem from fever. They’re actually how your body creates the fever in the first place. When your immune system detects an infection, it signals the brain’s internal thermostat to raise its target temperature. Your body then behaves as though it’s too cold: blood vessels near your skin constrict to trap heat, and your muscles start shivering to generate more warmth. That shivering is what you experience as chills. Once your blood temperature reaches the new, higher set point, the chills stop and you feel hot instead.
This means that treating the fever also treats the chills. As a fever reducer brings that thermostat set point back down, the shivering and cold sensations resolve on their own.
Acetaminophen vs. Ibuprofen
Both medications lower fever effectively, but ibuprofen has a slight edge. A meta-analysis in The Journal of Pediatrics found that ibuprofen reduced temperature more than acetaminophen at two, four, and six hours after a dose, with the difference being most pronounced at the four-hour mark. In practical terms, ibuprofen tends to bring a fever down a bit further and hold it there a bit longer.
That said, acetaminophen is gentler on the stomach and safe for people who can’t take anti-inflammatory drugs due to kidney issues, stomach ulcers, or certain heart conditions. Ibuprofen, as an anti-inflammatory, also helps with body aches and joint pain that often accompany fever, which can make it the better choice when you’re dealing with the full-body soreness of a flu or similar infection.
For adults, the maximum daily dose of acetaminophen is 4,000 milligrams across all products you’re taking. This is important because acetaminophen hides in many combination cold and flu medicines. Taking a standalone dose on top of a multi-symptom product can push you past the safe limit and put stress on your liver. Always check the active ingredients label on any cold, flu, or pain product before adding a separate fever reducer.
Alternating the Two Medications
Some people alternate acetaminophen and ibuprofen to keep a fever suppressed more consistently, and research does show this approach lowers temperatures more effectively than either drug alone within the first one to four hours. However, the American Academy of Pediatrics notes that alternating raises the risk of incorrect dosing and accidental overdose, so it’s not routinely recommended without guidance from a healthcare provider.
If you do alternate, keep a written log of what you took and when. Use only single-ingredient products. Multi-symptom formulas often contain acetaminophen or ibuprofen alongside other active ingredients, making it easy to double up without realizing it.
What Not to Take
Aspirin is an effective fever reducer for adults, but it should never be given to children or teenagers. Aspirin use during a viral illness has been linked to Reye’s syndrome, a rare but serious condition that causes swelling in the liver and brain. Because fever and chills are most often caused by viral infections, the safest approach is to keep aspirin out of the equation entirely for anyone under 18.
Home Remedies That Actually Help
Medication handles the fever itself, but a few simple measures can make a real difference in how you feel while you recover.
Rest is the single most important thing. Your immune system works best when your body isn’t spending energy on other tasks. Pushing through a fever often prolongs the illness. Stay home, lie down, and let yourself sleep as much as your body wants to.
Fluids matter more than usual because fever increases sweating and water loss through your skin and breathing. Your body’s fluid needs rise roughly 10% for every degree above 100.4°F. Water, broth, and electrolyte drinks all work. Chicken soup is a genuinely good option: it’s hydrating, easy to digest, and provides some nutrition when your appetite is low.
Cooling methods can help once the chills have passed and you feel overheated. A cool, damp washcloth on your forehead, cold beverages, ice chips, or a room-temperature shower that feels slightly cool are all reasonable options. A cold pack under your arm for up to 10 minutes at a time can also bring some relief. But skip all of these if you’re still in the chills phase. Trying to cool down while your body is actively trying to warm up will make you feel worse and won’t speed recovery.
Fever in Babies and Young Children
Infants under 3 months old with a rectal temperature of 100.4°F (38°C) or higher need immediate medical evaluation, regardless of how they appear. At that age, a fever can signal a serious infection that requires rapid assessment. Don’t give fever-reducing medication and wait to see what happens. Call your pediatrician or go to the emergency room.
For older children, acetaminophen and ibuprofen are both appropriate (ibuprofen is typically used in children 6 months and older). Dose by weight, not age, and use the measuring device that comes with the product rather than a kitchen spoon. Avoid cold packs on babies and young children, as they can’t reliably tell you if the temperature is too extreme for their skin.
When a Fever Needs Medical Attention
Most fevers resolve on their own within a few days as your immune system clears the underlying infection. But certain situations call for a doctor’s involvement. Contact your physician if your temperature exceeds 104°F (40°C), or if a lower fever persists for more than three days without improvement.
Seek immediate help if a fever comes with any of these: seizure, confusion, loss of consciousness, stiff neck, trouble breathing, severe pain, or visible swelling or inflammation anywhere on the body. These can indicate infections or conditions that need treatment beyond what over-the-counter medication can provide.