For adults, fevers can be uncomfortable, even frightening—but they're working for you, not against you.
A fever (a higher-than-normal body temperature) is not an illness. Rather, it's the body's response to an infection. Body temperature is regulated by part of your brain called the hypothalamus which acts like a thermostat. When you have an infection, substances released in your bloodstream prompt the hypothalamus to increase your body temperature. The fever helps your immune system work more effectively and may thwart bacteria and viruses, some of which cannot survive in higher temperatures.
The average normal temperature is 98.6 Fahrenheit , though body temperature varies based on time of day and may range about a point in either direction. In adults and children over the age of 12, a fever is considered to be an oral temperature above 99.5 degrees Fahrenheit, when not taking fever-reducing medications.
Infections often to blame
Infections cause most fevers, though certain other medical conditions also may be responsible. Some examples of fever-producing infections include:
- Colds, flu, sore throat, and infections of the ear, sinuses, and urinary tract
- Viral or bacterial stomach flu
- Pneumonia, appendicitis, and meningitis
Examples of medical conditions and situations that may lead to fever include:
- Rheumatoid arthritis, lupus, colitis, Crohn's disease, and certain cancers
- Heat exhaustion, exercise (especially in high heat or humidity), and dehydration
How to manage a fever
Low fevers associated with minor cold and flu symptoms can usually be managed at home by increasing fluid intake and getting lots of rest. The following steps may also help lower the fever:
- Get rid of excess clothing and blankets - keep the room temperature moderate
- Give the person a lukewarm bath or sponge bath
- Consider an over-the-counter (OTC) fever-reducing medication such as acetaminophen or ibuprofen - make sure you follow the package directions and check with your doctor or pharmacist first to make sure OTC fever reducers can be taken with other medications you might be taking
When to seek medical attention
Fevers of 103 degrees or higher or which last more than 48 to 72 hours or come and go for a week or more warrant a call to the doctor. Also seek medical attention if you develop any fever associated with a rash, confusion, headache, burning on urination, chest pain or other concerning symptoms or have an underlying medical condition such as heart disease, diabetes, a chronic lung condition, or other serious illness.