Body aches and chills usually show up together when your immune system is fighting off an infection, most commonly the flu or another respiratory virus. The fastest relief comes from a combination of the right over-the-counter pain reliever, steady fluid intake, and keeping your body at a comfortable temperature without overheating. Most people feel their worst on day two of a viral illness, with noticeable improvement by day three.
Why Aches and Chills Happen Together
When your body detects an infection, it raises its internal thermostat to create an environment that’s harder for viruses to thrive in. That rising temperature is what triggers chills: your brain now considers your normal body temperature “too cold,” so it signals your muscles to shiver and generate heat. Those same immune signals that raise your temperature also cause widespread inflammation in your muscles, which is why everything hurts at once.
This is why aches and chills tend to arrive as a package deal. They’re both side effects of your immune response, not the infection itself. The good news is that treating one often helps the other. Bringing your fever down reduces the shivering signal, and anti-inflammatory medications tackle both the fever and the muscle pain simultaneously.
Choose the Right Pain Reliever
Ibuprofen and acetaminophen are both effective, but they work differently. Ibuprofen reduces inflammation directly, which makes it particularly useful when body aches are your primary complaint. A meta-analysis of randomized controlled trials found that ibuprofen is more effective than acetaminophen at both lowering temperature and reducing pain, with meaningful differences appearing within four hours of taking a dose.
Acetaminophen is gentler on the stomach, so it’s a better choice if you’re also dealing with nausea or haven’t been able to eat. You can also alternate the two, since they work through different pathways. For adults, the over-the-counter ceiling for ibuprofen is 1,200 mg per day (400 mg three times daily), while acetaminophen tops out at 4,000 mg in 24 hours. Staying within those limits is important: ibuprofen can irritate the stomach lining, and too much acetaminophen can damage the liver, especially if you’re not eating much or drinking alcohol.
Stay Hydrated, and Add Electrolytes
Fever dramatically increases how much water you lose through your skin. For every degree above 100.4°F (38°C), your body’s evaporative water loss rises by roughly 10%. If you’re running a fever of 102°F, you’re losing significantly more fluid than normal even if you’re just lying in bed. That dehydration makes aches worse and can cause headaches and dizziness on top of everything else.
Water alone is fine for mild cases, but if your fever has been high for a day or more, drinks with sodium and potassium help your body actually retain the fluid you’re taking in. Broth, diluted sports drinks, or oral rehydration solutions all work. Sip steadily rather than forcing large amounts at once, especially if your stomach is unsettled. A practical way to gauge hydration: you should be urinating at least every eight hours. If you go longer than that, or your urine is very dark, you need more fluids.
Manage Your Temperature Without Overheating
The instinct when you have chills is to pile on blankets and heavy clothes. This feels comforting in the moment but can actually trap heat, push your fever higher, and make you feel worse once the chills pass. Instead, wear lightweight, breathable clothing and keep your room at a comfortable temperature. A single light blanket is reasonable if you’re shivering, but swap it out once the shivering stops.
A lukewarm bath can help bring your temperature down gently. Cold water or ice baths are counterproductive: they cause shivering, which forces your body to generate more heat and can actually raise your core temperature. The goal is gradual cooling, not a shock to the system.
Rest With Purpose
Sleep is when your immune system does its most aggressive work against infection. During the acute phase, especially the first two to three days, prioritize actual sleep over just lying on the couch watching TV. Keep the room slightly cool rather than warm, darken it if possible, and avoid the temptation to “push through” mild symptoms to get things done. Physical exertion while your body is fighting a fever diverts energy away from immune function and can extend your recovery.
The flu follows a fairly predictable arc. Day one hits suddenly, often with chills, headache, and body aches that can feel debilitating within hours. Day two is typically the worst, with the highest fever and most intense muscle pain. By day three, most people start turning a corner, with aches easing and fever beginning to drop. Full energy can take a week or more to return, but the acute misery of aches and chills is usually concentrated in that first 48-to-72-hour window.
When Antivirals Can Help
If your symptoms started within the last 48 hours and you suspect influenza, prescription antiviral medications can shorten the duration of fever and body aches. The CDC recommends antiviral treatment for anyone hospitalized, anyone with severe or worsening symptoms, and anyone at higher risk for complications (people over 65, pregnant women, those with chronic conditions like asthma or diabetes). For otherwise healthy adults, antivirals are an option if treatment can begin within two days of symptom onset.
The 48-hour window matters. Clinical benefit is greatest when treatment starts early. After that point, antivirals are less effective for mild cases, though they can still help people with severe or progressive illness. If you think you might qualify, call your doctor on day one rather than waiting to see if you improve.
Warning Signs That Need Medical Attention
Most episodes of aches and chills resolve on their own within a few days. But certain symptoms alongside a fever signal something more serious. Confusion or disorientation (beyond the brief fogginess that can happen at the peak of a high fever), a stiff neck where you can’t touch your chin to your chest, severe pain that prevents all normal activity, and signs of significant dehydration like no urination for eight or more hours all warrant immediate medical evaluation.
For infants under one month old, any fever is considered an emergency. For adults, a fever above 103°F that doesn’t respond to medication, a fever lasting more than three days, or symptoms that improve and then suddenly worsen (which can signal a secondary bacterial infection) are all reasons to get checked.
Putting It All Together
The most effective approach combines several strategies at once. Take ibuprofen or acetaminophen at the onset of symptoms. Start drinking fluids with electrolytes before you feel thirsty. Dress lightly, keep the room cool, and resist the urge to bury yourself under blankets. Cancel your plans for at least two days. If it’s flu season and you’re within that 48-hour window, contact your doctor about antivirals.
None of these steps will make you feel 100% better immediately, but together they meaningfully reduce the severity and duration of that miserable aches-and-chills phase. Most people notice the biggest improvement between day two and day three, and by day four or five, the worst is behind them.