When you have a fever and chills, the most effective things you can do are stay hydrated, rest, and let your body do its work while managing your comfort. Most fevers in adults under 103°F (39.4°C) aren’t dangerous and will resolve on their own within a few days. The chills you feel are your body’s way of generating heat to reach the higher temperature your immune system has temporarily requested.
Why Fever and Chills Happen Together
It seems contradictory to shiver while your body is heating up, but there’s a clear biological reason. When your immune system detects an infection, it releases signals that trigger the brain to produce a molecule called prostaglandin E₂. This molecule essentially turns up your internal thermostat, setting a new, higher target temperature. Your body then has to close the gap between where your temperature is and where the thermostat now says it should be.
To get there, your body does two things: it makes you shiver (generating heat through rapid muscle contractions) and it amplifies cold signals in the brain, making you feel chilled even though your actual temperature is rising. This is why you reach for blankets and warm drinks. You genuinely feel cold because your brain is processing the same signals it would if you were sitting in a freezing room. Once your body reaches the new set point, the chills typically ease and you may start feeling hot instead.
Immediate Steps for Comfort and Recovery
Drink more fluids than you normally would. A fever increases water loss through sweat and faster breathing. The baseline recommendation for adults is 1.5 to 2 liters of fluid per day (including what you get from food), and when you’re feverish, adding an extra glass each time you drink is a simple rule that works well. Water, broth, herbal tea, and diluted juice all count. If plain water feels unappealing, warm liquids can be especially soothing during the chills phase.
Eat if you can. The old saying “starve a fever” is wrong. Both fevers and colds cause dehydration and increased energy demands. You don’t need to force a full meal, but light, easy foods help keep your energy up and prevent you from feeling completely wiped out. Soup, toast, fruit, and yogurt are all good options.
Rest as much as possible. Your immune system works more efficiently when you’re not spending energy on other activities. Sleep is particularly valuable. If you can take time off work or responsibilities, this is the time to do it.
What to Wear and How to Stay Comfortable
The temptation during chills is to pile on heavy blankets and thick clothing. Resist going overboard. Overdressing can trap heat and push your temperature higher than it needs to go, while stripping down to almost nothing during chills will make you miserable without helping you recover faster. The sweet spot is light, breathable clothing and a comfortable room temperature. A single sheet or light blanket is usually enough.
If your fever shifts from the chills phase to feeling overheated, a room-temperature bath or shower (one that feels slightly cool to your skin) can help bring some relief. But skip the cooling methods entirely while you’re still shivering. Trying to cool off during the chills phase will only make you feel worse and won’t help your body heal.
When to Use Fever-Reducing Medication
Over-the-counter options like acetaminophen and ibuprofen can lower your temperature and ease the aching, headachy feeling that comes with fever. You don’t have to take them, though. A fever is part of your immune response, and letting it run its course is fine as long as you’re not dangerously hot or extremely uncomfortable.
If you do take medication, follow the dosing instructions on the package carefully. The key safety limit for acetaminophen is no more than 4,000 milligrams in a 24-hour period, and going over that threshold can cause serious liver damage. If you’re taking a combination product that contains both acetaminophen and ibuprofen, be careful not to also take a separate acetaminophen product at the same time, as the doses add up quickly.
When a Fever Needs Medical Attention
Most fevers break on their own within one to three days. If yours lasts longer than three days, it’s time to call your doctor even if it hasn’t reached a high number. A persistent low-grade fever can signal an infection that your body isn’t clearing on its own.
Temperature matters too. Fevers under 103°F (39.4°C) in adults are generally not cause for alarm. Once a fever climbs above 103°F, contact a healthcare provider for guidance. Fevers above 105.8°F (41°C) are a medical emergency: at that level, organs can start to malfunction.
Certain symptoms alongside a fever point to something more serious and warrant immediate care:
- Stiff neck combined with severe headache: this pattern can indicate meningitis, especially with sensitivity to light or confusion
- Difficulty breathing or chest pain
- Confusion, extreme drowsiness, or trouble staying awake
- Seizures
- A new rash, particularly one that doesn’t fade when you press on it
- Persistent vomiting that prevents you from keeping fluids down
Fever in Babies and Young Children
The rules are very different for infants. Any baby between 8 and 60 days old with a temperature at or above 100.4°F (38°C) needs medical evaluation, even if the baby looks well. Young infants can’t fight infections the same way older children and adults can, and a fever in this age range always requires professional assessment. For older children, the same general principles of hydration, rest, and comfort apply, but lower temperature thresholds for calling a pediatrician are the norm compared to adults.
What Recovery Looks Like
As your immune system gains the upper hand over the infection, your brain’s thermostat resets back to its normal set point. When this happens, you’ll likely start sweating as your body works to shed the extra heat. This is the “fever breaking” that people describe, and it’s a good sign. You may feel drained afterward, which is normal. Your body just spent significant energy fighting off an infection.
Give yourself a day or two of lighter activity even after the fever resolves. Jumping back into a full schedule immediately can leave you feeling run down and, in some cases, open the door to a secondary infection while your immune system is still recovering. Continue drinking extra fluids and eating well during this window.