When you have a fever and chills, the most effective immediate steps are to stay hydrated, dress in light layers, and consider an over-the-counter fever reducer if you’re uncomfortable. A temperature of 100.4°F (38°C) or higher counts as a fever, whether measured orally, rectally, or by ear. Most fevers from common infections resolve within a few days with basic home care.
Why Chills Happen With a Fever
Chills feel counterintuitive when your body is already running hot, but they’re actually the mechanism your body uses to generate heat. During an infection, your brain’s internal thermostat resets to a higher target temperature. To close the gap between your current body temperature and that new, higher target, your brain triggers shivering (rapid muscle contractions that produce heat) and constricts blood vessels near your skin so less warmth escapes. That’s why you feel freezing cold and want to bundle up, even though a thermometer would show you’re already warmer than normal.
Once your temperature reaches the new set point, the chills typically stop and you shift to feeling flushed and warm. When the infection starts to clear and the set point drops back to normal, you’ll sweat as your body works to shed the extra heat.
Fluids Are the Top Priority
Fever increases fluid loss through sweating and faster breathing, so dehydration is a real risk. Water, clear broth, and diluted juice all work well. For infants under 1 year, an oral rehydration solution like Pedialyte is a better choice than plain water or juice because it replaces both fluids and electrolytes in the right proportions.
Watch for signs that dehydration is setting in. In adults, that means urinating less often than usual or producing dark-colored urine. In babies and young children, the warning signs are fewer wet diapers (none in three hours is a red flag), a dry mouth, no tears when crying, or sunken eyes. Making plenty of clear urine is a reliable sign you’re staying well hydrated.
How to Stay Comfortable
Dress in light clothing and keep the room cool. Sleep with just a sheet or a light blanket. The instinct to pile on heavy covers during chills is strong, but over-bundling can trap heat and push your temperature higher. Once the chills pass and you feel warm, lighter layers will help your body regulate more easily.
A lukewarm sponge bath can help bring a fever down, especially in children. Use water between 90°F and 95°F (32°C to 35°C) and sponge for 20 to 30 minutes. Stop immediately if shivering starts, because shivering will raise the temperature again and make the child more uncomfortable. Never use cold water, ice, or rubbing alcohol. These cool the skin too fast, triggering intense shivering and potentially dangerous drops in body temperature.
When to Use a Fever Reducer
Fever itself isn’t dangerous in most cases. It’s part of your immune response. But if you’re miserable, achy, or unable to sleep, an over-the-counter fever reducer can help you feel better while your body fights the infection. Acetaminophen and ibuprofen are the two main options for both adults and children.
For children under 12, liquid acetaminophen (160 mg per 5 mL) can be given every 4 hours based on the child’s weight, up to 5 doses in 24 hours. Children over 12 can take extra-strength tablets every 6 hours, with a maximum of 6 tablets per day. Do not give acetaminophen to children under 2 without a pediatrician’s guidance, and do not give 500 mg extra-strength products to children under 12.
For adults, follow the dosing instructions on the package and avoid exceeding the daily maximum, which is clearly printed on the label. Taking more than directed, especially with acetaminophen, can cause serious liver damage.
Temperature Thresholds That Matter
Not every fever needs medical attention, but certain numbers and situations change the calculus significantly.
- Newborns under 1 month: A rectal temperature of 100.4°F (38°C) or higher is an emergency. Go to the nearest emergency room immediately.
- Infants 1 to 3 months: The same 100.4°F threshold applies, but the next step is calling your pediatrician. If you can’t be seen right away, head to the ER.
- Children 7 to 24 months: A rectal temperature above 102°F (38.9°C) that lasts longer than one day warrants a call to the pediatrician, even without other symptoms.
- Children over 2: A fever lasting longer than three days should be evaluated.
- Adults: Fevers of 103°F (39.4°C) or higher usually come with visible illness and deserve medical evaluation.
Red Flag Symptoms to Watch For
A fever paired with certain other symptoms can signal something more serious than a typical viral infection. A stiff neck combined with a high fever, severe headache, and sensitivity to light are hallmark signs of meningitis, which requires immediate medical care. Vomiting, confusion, trouble waking up, and seizures alongside a fever are also emergencies.
A rash that appears during a fever, particularly one that doesn’t temporarily fade when you press on it, can indicate a serious bacterial infection. In children, unusual drowsiness, persistent crying, or a refusal to eat or drink alongside a fever are reasons to seek care promptly rather than waiting it out.
What a Normal Recovery Looks Like
Most viral fevers follow a predictable arc. The temperature rises over the first day or two, often peaking in the late afternoon or evening, then gradually comes down as the immune system gains control. The whole cycle typically wraps up within a few days. During recovery, it’s common for the fever to break and return once or twice before fully resolving.
During this window, the goal is comfort and hydration, not eliminating the fever entirely. A low-grade fever that you can tolerate without medication is your immune system doing its job. Rest, fluids, light clothing, and fever reducers when needed will get most people through it without complications.