Why Do Fevers Cause Chills?

Fevers are often accompanied by chills—shaking, shivering, and feeling cold. This odd sensation of feeling like you are overheating and freezing at the same time occurs because of the sharp contrast between your environment and your body: When your body temperature is higher than normal, the air and environment around you will feel colder than it usually does. As a result, muscles rapidly contract and relax in an effort to produce body heat, which you experience as "the chills."

Chills tend to be more common in children and typically occur at the start of an illness such as the flu.

Your first reaction to discomfort may be to put on more clothes or blankets to get warm. The problem with doing this is that bundling up will increase your body temperature further, possibly perpetuating discomfort and contributing to dehydration. The physical act of shivering or shaking due to chills itself can also raise your internal body temperature.

Figuring out how to get comfortable and also bring your temperature down can be a bit of a balancing act.

If the fever is 102 degrees F or less and you do not have any serious signs and symptoms (see below), you do not need to see a healthcare provider for treatment.

You can treat your fever at home by:

• Taking fever-reducing medications: Tylenol (acetaminophen) or Motrin (ibuprofen) can help reduce your fever and make you more comfortable. However, they can take an hour to work, so you may have to take other steps in the meantime.
• Warming up, but not bundling up: Using an extra blanket or two to stop yourself from shivering when you have a fever is fine, just don't overdo it. Remove coverings once you get comfortable. As for clothing, wear items that are appropriate for the weather rather than layering.
• Staying hydrated: Drinking plenty of clear liquids when you are sick with a fever is essential. Avoid alcohol.
• Sponge bathing: Dapping yourself with a washcloth soaked in lukewarm water (about 70 degrees F) may help bring down a fever, as evaporation cools the skin and reduces body temperature. Note, though that cold water may increase fever because it can trigger chills.

Fevers are not inherently dangerous. They are a natural defense against illness. And while most fevers resolve on their own after a few days, fever and chills can sometimes be a sign of a more serious condition, such as meningitis.

Call your doctor or seek medical attention if a fever is accompanied by these symptoms:

• Stiffness of the neck
• Confusion or irritability
• Sluggishness
• A bad cough
• Shortness of breath
• Abdominal pain or burning
• Frequent urination

In addition, call your doctor or seek medical attention for the following:

• In a child younger than 3 months: A temperature of 100.3 degrees F or greater
• Children ages 3 months to 1 year: A fever of 101 degrees F or greater that lasts more than 24 hours
• In older children and adults: A fever greater than 103 degrees F that does not respond to fever-reducing medicine, or a fever that does not improve after three days or has lasted more than five days

Fever and chills often occur together, but they aren't necessarily something to be worried about. If you are concerned that shaking or shivering is uncontrollable or if it does not stop once the fever is down, contact your healthcare provider or seek medical attention.