Why Do Fevers Cause Chills?

Fevers are often accompanied by chills—shaking, shivering, and feeling cold. This odd sensation of feeling like you are burning with fever and freezing at the same time occurs because 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. It happens in response to both cold air temperatures and an increase in your internal body temperature. Chills tend to be more common in children and typically occur at the start of an illness such as the flu.

A fever is the body's natural reaction to infection. When a virus or bacteria invades, one of the immune system's defenses is to raise the body temperature because virus and bacteria are less able to multiply at temperatures greater than 98.6 degrees F.

Getting comfortable when you have a fever and chills can be difficult. Your first reaction to discomfort is probably to put on more clothes or blankets so you will feel warm. The problem with doing this is that bundling up in even more layers will also increase your body temperature further.

If the fever is mild, 102 degrees F or less you do not need to see a provider for treatment. You can treat the fever at home by:

• Taking fever-reducing medications: acetaminophen (Tylenol) or ibuprofen (Motrin or Advil) 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.
• Wearing warm clothing without 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. Use the extra layers to get comfortable so you no longer have chills and then take them off, wearing clothes that are appropriate for the weather. Don't bundle up a young child with a fever; keep her dressed lightly and comfortably.
• Staying hydrated: drinking plenty of clear liquids (not alcohol) when you are sick with a fever is essential.
• Sponging with lukewarm water, about 70 degrees F, may help bring down a fever. This is because evaporation cools the skin and reduces body temperature. However, cold water may increase the fever as it can trigger chills.

Probably the most essential thing to remember when you or your child has a fever is not to panic. Fevers are not inherently dangerous. They are a natural defense against illness. It is your body's way of fighting off infections by making the environment in your body uninhabitable for germs.

While most fevers resolve on their own after a few days, fever and chills may 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 the 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 between 3 months and 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 health care provider or seek medical attention.