Most fevers don’t need aggressive treatment. A fever is your body’s natural defense against infection, and in most cases, the goal isn’t to eliminate it completely but to keep yourself or your child comfortable while the immune system does its work. A temperature of 100.4°F (38°C) or higher, measured rectally or with an ear thermometer, is considered a fever. For oral readings, the threshold is 100°F (37.8°C).
Why Your Body Runs a Fever
When your immune system detects an invader like a virus or bacteria, it triggers a chain reaction that produces a signaling molecule called prostaglandin E2. This molecule acts on the hypothalamus, the part of your brain that works like a thermostat, and raises your body’s target temperature. Your brain then generates heat through shivering and reduces heat loss by narrowing blood vessels near the skin. That’s why you feel cold and shaky even though your temperature is climbing.
This elevated temperature actually helps your immune system. Many pathogens reproduce less efficiently at higher temperatures, and some of your immune cells work faster when things heat up. So while a fever feels miserable, it’s doing something useful. Treatment is about managing discomfort, not fighting your body’s response.
Over-the-Counter Fever Reducers
The two main options are acetaminophen (Tylenol) and ibuprofen (Advil, Motrin). Both lower fever effectively, but they work differently and have different safety profiles.
Acetaminophen can be taken every 4 to 6 hours, with no more than 5 doses in 24 hours. For adults and children over 12, the daily maximum is 4,000 milligrams. Do not give acetaminophen to infants under 8 weeks old.
Ibuprofen can be taken every 6 to 8 hours, with no more than 4 doses in 24 hours. The daily maximum for adults and older children is 1,200 milligrams when used for fever or mild pain. Do not give ibuprofen to infants under 6 months old unless directed by a pediatrician. Ibuprofen also reduces inflammation, which can help if the fever comes with body aches or a sore throat.
For children, dosing is based on weight, not age. The number on the box that corresponds to your child’s weight is more accurate and safer than going by age alone.
Alternating Between Two Medications
If one fever reducer alone isn’t providing enough relief, you can alternate between acetaminophen and ibuprofen. The key rule: don’t take both at the same time. Take one first, then switch to the other 4 to 6 hours later. You can continue rotating every 3 to 4 hours throughout the day. Multiple studies have found that this approach provides better symptom control than either medication alone.
If you’re alternating for more than three days, it’s worth checking in with a healthcare provider. For children under 12, contact your pediatrician to confirm the right weight-based dose before starting this routine. Keeping a written log of what you gave and when helps prevent accidental double-dosing, especially in the middle of the night when things get foggy.
Non-Drug Approaches That Actually Help
You’ve probably heard that a lukewarm sponge bath can bring a fever down. Research tells a more nuanced story. One study comparing acetaminophen alone to acetaminophen plus a 15-minute tepid sponge bath found that sponge-bathed children cooled slightly faster in the first hour, but there was no meaningful temperature difference between the two groups over two hours. The sponge-bathed children did, however, have significantly higher discomfort scores. In other words, it made them more miserable without a lasting benefit. Current guidance discourages sponge baths for fever, reserving them for cases of heat stroke or other forms of hyperthermia where the body’s thermostat isn’t the problem.
What does help:
- Fluids. Fever increases water loss through sweat and faster breathing. Small, frequent sips of water, broth, or an electrolyte drink prevent dehydration, which can make you feel far worse than the fever itself.
- Light clothing and bedding. Bundling up traps heat. A single layer and a light blanket let your body release excess warmth.
- Rest. Your immune system consumes enormous energy fighting infection. Sleep and low activity let your body direct resources where they’re needed.
- Room temperature. A comfortable, slightly cool room (around 68 to 72°F) helps without causing shivering, which would actually raise your core temperature.
When a Fever Needs Medical Attention
Age matters enormously with fevers. Any fever in a baby younger than 3 months old warrants an immediate call to your pediatrician, regardless of how high the temperature is. Young infants don’t have mature immune systems, and a fever can signal a serious infection that needs rapid evaluation.
For babies between 7 and 24 months, a rectal temperature above 102°F (38.9°C) that lasts longer than one day, even without other symptoms, should be evaluated. For children of any age, a fever lasting longer than three days needs professional assessment.
In adults, the temperature number matters less than the accompanying symptoms. Seek urgent care if a fever comes with a stiff neck, severe headache, confusion or unusual drowsiness, difficulty breathing, skin or lips that look blue or gray, or a rash that doesn’t fade when you press on it. These can point to meningitis, sepsis, or other conditions that need treatment fast.
Febrile Seizures in Children
Febrile seizures affect some children between 6 months and 5 years old, typically during a rapid rise in temperature. They look terrifying but are usually harmless and don’t cause brain damage or epilepsy. The simple type lasts a few seconds to 15 minutes. The complex type can last longer than 15 minutes.
If your child has a febrile seizure, here’s what to do: gently lay them on the floor on their side, which prevents choking on saliva or vomit. Don’t place them on a bed or table, don’t try to hold them down, and don’t put anything in their mouth. Note the time the seizure starts. If it lasts longer than 5 minutes, call 911. Once the seizure ends, your child will likely be sleepy and confused for a short time, which is normal.
Febrile seizures cannot be prevented by treating the fever with medication. They’re triggered by the speed of the temperature change, not the peak temperature, so giving acetaminophen or ibuprofen at the first sign of fever won’t necessarily stop one from happening.
How Long Fevers Typically Last
Most fevers caused by common viral infections (colds, flu, stomach bugs) resolve within 3 days. The fever often peaks in the late afternoon or evening and dips in the morning, creating a roller-coaster pattern that can make you think you’re better before the temperature climbs again. This is normal. Bacterial infections like strep throat or urinary tract infections can cause fevers that persist until you start antibiotics. If your fever follows a pattern where it disappears for a day or two and then returns, that’s worth mentioning to your doctor, as it can suggest a different type of infection or an inflammatory condition.