A fever is your body’s way of fighting infection, and most fevers can be managed safely at home with rest, fluids, and over-the-counter medication. An oral temperature of 100°F (37.8°C) or higher counts as a fever in both adults and children. In most cases, the goal isn’t to eliminate the fever entirely but to stay comfortable and hydrated while your immune system does its work.
Why Your Body Runs a Fever
Fever isn’t a malfunction. It’s an intentional response your immune system triggers to gain an advantage over whatever is making you sick. Research from the National Institutes of Health shows that at higher body temperatures, your infection-fighting cells multiply faster, produce more signaling molecules to coordinate an immune attack, and become more metabolically active. At the same time, the cells that normally dial down immune responses become less effective, letting your body mount a stronger defense.
This is why many doctors don’t recommend aggressively treating a low-grade fever if you’re otherwise comfortable. A temperature of 100°F to 101°F in an adult who feels okay may actually be helping your body recover faster. That said, higher fevers cause real discomfort and can be risky, so knowing when and how to bring the temperature down matters.
Step-by-Step Home Care
The basics of fever management are simple: stay cool, stay hydrated, and rest.
- Drink more fluids than usual. Fever increases fluid loss through sweat and faster breathing. Water, diluted juice, and broth all work. For children under 1, use an oral rehydration solution like Pedialyte, which contains the right balance of water, sugar, and electrolytes. Pedialyte ice pops are another option for toddlers who resist drinking.
- Dress lightly. Wear one layer of lightweight clothing and keep the room cool. Sleep with just a sheet or a light blanket, even if you feel chilly. Bundling up traps heat and can push your temperature higher.
- Rest as much as possible. Your body is burning extra energy to mount an immune response. Physical activity raises your core temperature further and slows recovery.
You may have heard that a lukewarm bath can help bring a fever down. It can offer temporary relief, but avoid cold water or ice baths. Cold triggers shivering, which actually generates more heat and raises your core temperature.
When to Use Fever-Reducing Medication
Over-the-counter fever reducers like acetaminophen (Tylenol) and ibuprofen (Motrin, Advil) are the standard options. You don’t need to take them for every fever, but they help when discomfort is keeping you from sleeping, eating, or drinking enough fluids.
For adults, acetaminophen and ibuprofen are both effective. Follow the dosing instructions on the package, and don’t exceed the daily maximum listed on the label. Acetaminophen is processed by the liver, so avoid it if you’re drinking alcohol or have liver problems. Ibuprofen can irritate the stomach, so take it with food.
For children, dosing is based on weight, not age. Acetaminophen can be given every 4 hours, while ibuprofen can be given every 6 hours. A 24-pound toddler, for example, takes 1 teaspoon (5 ml) of children’s liquid acetaminophen or 1 teaspoon of children’s liquid ibuprofen. Always use the measuring device that comes with the medication, not a kitchen spoon. Ibuprofen is not recommended for babies under 6 months old. Never give aspirin to children or teenagers, as it’s linked to a rare but serious condition called Reye’s syndrome.
Watch for Dehydration
Dehydration is the most common complication of a fever, especially in young children. In adults, the warning signs are dark-colored urine, urinating less often than normal, extreme thirst, dizziness, and confusion. If you pinch the skin on the back of your hand and it doesn’t flatten back right away, that’s another sign you’re significantly dehydrated.
In infants and toddlers, watch for no wet diapers for three hours or longer, a dry mouth, crying without tears, sunken eyes, and unusual crankiness or lack of energy. A sunken soft spot on the top of a baby’s head is a particularly telling sign. If you notice any of these, increase fluids immediately. If your child refuses to drink or the signs don’t improve, seek medical care.
How to Take an Accurate Temperature
Where you measure matters. Rectal readings run about 0.5°F to 1°F higher than oral readings. Ear (tympanic) thermometers also read slightly higher than oral. Armpit and forehead readings tend to run 0.5°F to 1°F lower than oral, which means they can underestimate a fever.
For babies and toddlers under 3, a rectal thermometer is the most accurate option. For older children and adults, oral or ear thermometers are reliable and more practical. If you’re using a forehead or armpit thermometer and the reading seems borderline, consider rechecking with an oral or ear thermometer to confirm.
A fever in children is defined as a rectal, ear, or forehead temperature of 100.4°F (38°C) or higher, an oral temperature of 100°F (37.8°C) or higher, or an armpit temperature of 99°F (37.2°C) or higher.
Fever in Babies Under 3 Months
Any fever in a baby younger than 3 months is treated as a medical emergency, regardless of how the baby looks or acts. If your newborn has a rectal temperature of 100.4°F or higher, go to the emergency room. At this age, a fever can signal a serious bacterial infection that a baby’s immature immune system can’t fight on its own. Don’t give fever-reducing medication and wait to see if the temperature drops. Get evaluated immediately.
When a Fever Needs Medical Attention
For babies between 7 and 24 months, call your pediatrician if a rectal temperature above 102°F (38.9°C) lasts longer than one day, even without other symptoms. For children over age 2, a fever lasting more than three days warrants a call. For adults, contact your doctor if your temperature reaches 103°F (39.4°C) or higher.
Regardless of the number on the thermometer, seek immediate medical help if a fever comes with any of these symptoms:
- Seizure
- Loss of consciousness or confusion
- Stiff neck
- Trouble breathing
- Severe pain anywhere in the body
- Swelling or inflammation in any body part
- Pain when urinating or foul-smelling urine
A fever over 104°F (40°C) in an adult requires a call to your doctor, even without other symptoms. At that level, the risks of the fever itself begin to outweigh any immune benefit.
What to Do if Your Child Has a Febrile Seizure
About 2% to 5% of children between 6 months and 5 years will experience a febrile seizure, which is a convulsion triggered by a rapid rise in body temperature. It looks alarming: your child may shake uncontrollably, stiffen up, lose consciousness, or lose bladder or bowel control. Their eyes may roll back.
If this happens, stay calm and note the time. Gently lower your child to the floor (not a bed or table, where they could fall). Turn them on their side to prevent choking on saliva or vomit. Do not put anything in their mouth and do not try to hold them down. Most febrile seizures stop on their own within a minute or two and do not cause lasting harm. If the seizure lasts longer than five minutes, call 911 immediately.
After a first febrile seizure, your child should be evaluated by a doctor even if the seizure was brief and they seem fine afterward. Febrile seizures are frightening but rarely dangerous, and most children who have one never have another.