If you have a fever and chills, the most important things to do right away are rest, drink fluids, and use a light blanket if you’re shivering. A fever is defined as a body temperature of 100.4°F (38°C) or higher, and chills are your body’s natural way of generating heat to reach that new, higher set point. Most fevers from common infections resolve within three to five days, and the steps below will help you stay comfortable and recover faster.
Why Fever and Chills Happen Together
Chills and fever feel contradictory, but they’re part of the same process. When your immune system detects an infection, it sends chemical signals to the brain’s temperature control center. That center essentially raises the thermostat. Because your actual body temperature is now “too low” relative to this new setting, your brain triggers shivering to generate heat and bring you up to the target. That’s why you feel freezing cold even though your skin is hot to the touch.
Once your temperature reaches the new set point, the shivering stops and you start to feel warm or even overheated. Later, when the fever breaks, your thermostat resets back to normal and you sweat to cool down. This cycle of chills, fever, and sweating can repeat multiple times over the course of an illness.
Step One: Rest
Your immune system works best when your body isn’t spending energy on other things. Stay home from work or school and lie down whenever you can. Trying to push through a fever often prolongs the illness. Sleep is the single most effective thing you can do during the acute phase, so if you can doze off, let yourself.
Step Two: Stay Hydrated
Fever increases fluid loss through sweating, faster breathing, and sometimes vomiting or diarrhea. Dehydration makes you feel worse and can slow recovery. Drink water, herbal tea, broth, or an oral rehydration solution throughout the day, even if you’re not thirsty. Avoid caffeinated and high-sugar drinks like soda, coffee, and energy drinks, which can worsen dehydration.
Watch for signs that you’re falling behind on fluids: dark-colored urine, urinating less often than usual, extreme thirst, dizziness, or skin that doesn’t flatten back right away after you pinch it. In children, look for a dry mouth, no tears when crying, fewer wet diapers, sunken eyes, or unusual crankiness.
Managing Comfort During Chills
When you’re shivering, it’s fine to wrap up in a blanket or put on an extra layer. But don’t pile on so many covers that you overheat. Too many blankets can push your body temperature even higher and cause more sweating, which increases your risk of dehydration. Use one comfortable blanket, and remove it once the chills pass and you start feeling warm.
You may have heard that a lukewarm sponge bath helps bring a fever down. Research on this is not encouraging. One study comparing fever-reducing medication alone to medication plus a 15-minute tepid sponge bath found no meaningful temperature difference after two hours, and the sponge-bathed group was significantly more uncomfortable, with more crying, shivering, and goosebumps. Medication alone works just as well without the added misery.
Fever-Reducing Medication
Acetaminophen (Tylenol) and ibuprofen (Advil, Motrin) are the two main options for bringing a fever down and easing the aches that come with it. You don’t always need to take them. A moderate fever is your body fighting infection, so if you’re uncomfortable but managing, it’s fine to ride it out. If the fever is making you miserable, preventing sleep, or climbing above 102°F, medication can help.
Follow the dosage instructions on the package carefully, and don’t exceed the recommended amount. Avoid switching back and forth between acetaminophen and ibuprofen without guidance from a doctor, because it’s easy to accidentally double up. Don’t give ibuprofen to anyone who is dehydrated, vomiting heavily, or has kidney problems. And never give aspirin to anyone under 20 years old due to the risk of a rare but serious condition called Reye’s syndrome.
Dosing for Children
Children’s doses are based on weight, not age. Always use the measuring device that comes with the product rather than a kitchen spoon. Acetaminophen can be given up to five times in 24 hours, while ibuprofen tops out at four doses. Don’t give acetaminophen to infants under 2 months old, and don’t give ibuprofen to babies under 6 months old.
What’s Probably Causing It
The vast majority of fevers with chills come from common viral infections. Upper respiratory infections (colds, flu, COVID) are the most frequent culprits. Over 100 different viruses can infect the respiratory tract, with rhinoviruses, influenza, and respiratory syncytial virus (RSV) among the most common. Stomach bugs, both viral and bacterial, also frequently cause fever.
Bacterial infections tend to produce higher fevers. Strep throat accounts for 20 to 30 percent of sore-throat-plus-fever cases. Pneumonia, ear infections, and urinary tract infections are other common bacterial sources. In pneumococcal pneumonia, for example, the pattern is distinctive: several days of flu-like symptoms followed by a sudden onset of shaking chills and high fever.
High fever alone doesn’t confirm a bacterial infection, but it does increase the likelihood of one. If your fever climbs above 102.4°F (39.1°C), that’s considered high-grade and worth paying closer attention to.
How Long a Fever Typically Lasts
With the flu, fever usually starts dropping around day three and is gone or nearly gone by day four. Most healthy adults recover fully within five to seven days, though fatigue and a lingering cough can stick around for up to two weeks. Other viral infections follow a similar pattern, with the worst of the fever concentrated in the first two to three days.
Stay home until at least 24 hours after your fever breaks without the help of fever-reducing medication. This is both for your own recovery and to avoid spreading the infection.
A fever lasting longer than seven days, or one that goes away and then comes back, is a signal that something more complicated may be going on. The same applies if your symptoms are worsening rather than gradually improving after the first few days.
Warning Signs That Need Urgent Attention
Most fevers are harmless and self-limiting, but certain symptoms alongside a fever require immediate medical care:
- Confusion or difficulty staying conscious: This can signal the infection is affecting your brain or that dehydration has become severe.
- Difficulty breathing or chest pain: Could indicate pneumonia or another serious complication.
- Stiff neck with severe headache: A classic warning sign of meningitis.
- Seizure: Seek emergency care immediately.
- Severe abdominal pain: May point to appendicitis or another condition requiring treatment.
- Inability to keep fluids down: Persistent vomiting combined with fever can lead to dangerous dehydration quickly.
- Temperature reaching 103°F (39.4°C) or higher alongside any of the symptoms above.
Fever in Babies and Young Children
Any fever of 100.4°F or higher in a baby under 3 months old needs a call to the pediatrician right away. For older infants and children, look for rapid or difficult breathing, a rash, inconsolable crying, difficulty waking up, or refusal to drink fluids. A fever of 105°F or higher in any child is a medical emergency.