Chills are produced when your muscles repeatedly expand and contract to generate heat. They can be constant and continue for as long as an hour, or they can occur periodically, with each episode lasting for several minutes.
Chills can occur after exposure to a cold environment. They also occur as a response to a bacterial or viral infection that causes a fever, and are commonly associated with the following conditions:
- bacterial or viral gastroenteritis
- infectious mononucleosis
- influenza (flu)
- strep throat
- urinary tract infections
Chills are more common in young children than in adults. This may be because children are more prone to developing fevers than adults, and because their fevers tend to be higher than those that affect adults. Minor illness that do not cause a fever in adults can produce fevers in children.
The National Institutes of Health recommend the following guidelines for treating a fever with chills in adults and children (NIH):
Home Care for Adults
Treatment is usually based on whether your chills are accompanied by a fever, as well as on the severity of the fever. If your fever is mild (102°F or less) and you have no other serious symptoms, you do not need to see a doctor. You should rest and drink plenty of liquids.
Covering yourself with layers of blankets or clothing when you have a fever and chills may actually raise your body temperature. Sponging your body with lukewarm water (about 70°F) or taking a cool shower can help reduce a fever. Cold water, however may trigger an episode of chills.
Over-the-counter medications, such as aspirin, acetaminophen (Tylenol), or ibuprofen (Advil), can also help to lower a fever and fight chills. As with any medication, follow the dispensing directions carefully. Aspirin and ibuprofen will lower your fever and reduce inflammation. Acetaminophen (Tylenol) will bring down a fever; but not reduce inflammation. Acetaminophen can be toxic to your liver if not taken as directed.
Call your doctor if your fever and chills do not improve after three days of home care, or if they are accompanied by any of the following symptoms:
- stiff neck
- significant cough or shortness of breath
- confusion, sluggishness, or irritability
- abdominal pain or painful urination
- frequent urination or lack of urination
- forceful vomiting
- unusual sensitivity to bright light
Home Care for Children
Treating a child with chills and fever depends on the child’s age, his or her temperature, and any accompanying symptoms. In general, if your child’s fever is between 102°F and 103.5°F and he or she is uncomfortable, you can give him or her acetaminophen in tablet or liquid form. Follow the dosing instructions on the package carefully.
If your child’s fever rises higher than 103.5°F, you can also bathe him or her in lukewarm water, adding warm water as necessary to prevent shivering.
Never bundle feverish children in heavy blankets or layers of clothing. Dress them in lightweight clothing and give them water or other liquids to keep them hydrated.
Never give aspirin to children under the age of 18 because of the risk of Reye’s syndrome. Reye’s syndrome is a rare but serious disorder that can affect children who were given aspirin while they had a viral infection.
Call a doctor in the case of any of the following:
- a fever of 101°F or higher in a child younger than three months old
- a fever that continues for more than 24 hours in a child between three months and one year old
- a fever that does not fall below 103°F after one to two hours of treatment
Your doctor will ask you for details about your chills and fever, including:
- Do the chills actually make you shake or do you just feel cold?
- What was your highest body temperature that was also accompanied by chills?
- Have you had chills just once or have you had repeated episodes of chills?
- How long did each episode of chills last?
- Did the chills begin after exposure to something to which you or your child is allergic? Did they begin suddenly?
- What are your other symptoms?
Your doctor will perform a physical examination and may order diagnostic tests. He or she will look for signs that your fever is caused by a bacterial or viral infection. Diagnostic tests may include:
- a blood test, including a blood culture to detect bacteria or fungi in the blood
- a sputum culture of secretions from the lungs and bronchi (tubes in the lungs)
- urinalysis: physical, chemical, and microscopic examination of your urine to detect and measure bacteria in the urine
- a chest X-ray to detect pneumonia, tuberculosis, or other infections
Your doctor may prescribe an antibiotic if he or she finds that you have a bacterial infection, such as strep throat or pneumonia.
Chills and fever are signs that something is wrong. If you treat your chills and fever but they persist, you should see your doctor to determine the underlying cause.
If your fever goes untreated, you may experience severe dehydration and hallucinations. Children ages six months to five years may also have fever-induced seizures (febrile seizures). Luckily, these seizures do not typically cause long-term health problems.