If you've always believed that you can detect a fever by touching someone's forehead, I then think again.

The abdomen is actually more likely to feel warm when someone has a fever. However, a thermometer is the only way to accurately measure body temperature.

Here are six other common-and potentially dangerous-myths about fever...

Myth 1: All adults have a normal body temperature of 98.6'F. "Normal" body temperature is conventionally said to be 98.5'F, but it actually varies. For some people, 98'F is normal, and for others, it could be 99'F. Body temperature usually rises during the course of the day-your temperature may be 98.2'F in the morning and rise to 99.4'F in the late afternoon.

Normal temperature tends to decline as you age. According to a study conducted at Yeshiva University in New York City, the average oral temperature of 150 healthy people age 65 and older was 97.5'F. Because their normal body temperature tends to be lower, some older adults may be seriously ill-they may have pneumonia or a widespread infection-yet appear to have no fever at all.

Myth 2: A fever always means that you have an infection. Not necessarily. Bacterial pneumonia or a bladder infection is typically accompanied by a fever. Elevated body temperature also occurs during a number of viral illnesses, such as influenza, gastroenteritis (stomach flu)-even the common cold.

However, a fever can also signal an allergic reaction...dehydration...inflammation...a hormone disorder, such as hyperthyroidism...or an autoimmune disease, such as rheumatoid arthritis. Medications, such as antibiotics, narcotics, barbiturates and antihistamines, can trigger a fever as well. Cancer, especially leukemia or lymphoma, can cause a persistent fever of 100'F to 101'F.

Myth 3: Fever should always be treated. Most of the time, you don't need to do anything to reduce a fever Unless it goes quite high (above 104'F in an adult), it causes no permanent damage-but you will feel uncomfortable. Some doctors suggest letting a fever run its course. That way, you won't undermine your body's natural defense process.

If you choose to let a fever run its course, drink lots of fluids to avoid becoming dehydrated by the increased metabolism that accompanies fever.

Even if you're not thirsty, keep a glass of water or juice at your bedside and take sips often. Eat soups and suck on popsicles. Take lukewarm baths or showers.

Myth 4: Aspirin is the best medicine for a fever. The most common antipyretics-fever reducers-are available over-the- counter. They include acetaminophen (Tylenol) and aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil) and naproxen (Aleve).

As far as effectiveness goes, there's little difference among them-no solid evidence shows that any of these drugs works faster or better than the others at reducing fever.

Important: Never exceed the dosage recommendations without first discussing it with your physician.

Choose the best fever-reducer on the basis of your own medical profile and the medication's potential side effects...

If you take daily aspirin therapy: Take acetaminophen. NSAIDs can sometimes undermine the benefits of aspirin therapy, according to the latest studies.

If you have blood pressure: Take acetaminophen. Aspirin and other NSAIDs can raise blood pressure.

If you have kidney disease: Take acetaminophen. Aspirin and other NSAIDs can damage the kidneys.

If you're susceptible to gastrointestinal problems: Take acetaminophen. Aspirin and other NSAIDs can irritate the digestive system and cause bleeding.

If you have asthma: Take acetaminophen. Aspirin and other NSAIDs may trigger an attack.

If you have liver disease or drink more than three alcoholic beverages a day: Take aspirin or another NSAID. Acetaminophen can harm the liver in some people.

Important: Don't give aspirin to anyone younger than age 15-it can cause Reye's syndrome, a potentially life-threatening condition that causes swelling of the brain and degeneration of the liver.

Myth 5: A fever means you're contagious. Not so. A person who has an upper respiratory tract infection may be contagious early on, when he/she has a runny nose but no fever. On the other hand, a person who has a bacterial infection can still be running a fever after several days of antibiotic treatment but no longer be contagious.

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