About Fevers

A fever is a higher-than-normal body temperature. It is typically related to an infection in the body but is not considered an infection or illness itself. Fever often accompanies respiratory illnesses, such as colds and flu. However, it can result from a full range of infections and conditions, including those as common as stomach viruses and those as serious as cancer. It may be present with both bacterial and viral infections. Even toxins can cause a fever.

The Facts

• Often doctors suggest taking a temperature rectally, as this method proves far more accurate than its oral counterpart. A rectal temperature of 100.5 degrees F is considered a fever. Orally, a fever is usually considered a temperature above 99.5 degrees F. However, it is important to keep in mind that a person may have a fever at an even lower temperature, depending on the normal body temperature for that person.

Identification

• Fever is not just any temperature rise. A person's body temperature is normally at or around 98.6 degrees F, but that temperature can vary according to activity level, age and even the time of day. Furthermore, each person's normal body temperature may be a bit different. Your body temperature is normally highest in the evening hours, but everything from stress to heavy clothing to exercise can cause it to rise. A sustained increase in temperature in the presence of an infection or illness, even one that you are unaware of, is a fever.

Misconceptions

• Many people mistakenly think fever is an illness. This is not the case, as a fever is in fact your body's defense against an infection. Usually, bacteria and viruses are able to thrive in a body that is at normal or average body temperature. When the temperature goes up, however, the body gains a leg up on fighting the infection. Also, fevers actually work to stimulate the immune system, causing it to create more white blood cells. It also stimulates the production of antibodies.

Risk Factors

• Brain damage is a risk with very high fevers. However, many parents worry over this possibility unnecessarily. Usually, brain damage only becomes a risk when the body temperature reaches 107.6 degrees F. Fortunately, temperatures this high are very rare. Even untreated fevers rarely climb higher than 105 degrees F. The risk of reaching these extreme temperatures does increase, however, when a person is overdressed or in a very hot place and unable to get out, such as a car with all the windows closed. Seizures may also occur with very high fevers, particularly in children, but they are not common. When they do occur, they usually do not cause lasting problems.

Effects

• Besides having an elevated temperature, a person with a fever may feel tired and hot, and chills or hot-and-cold flashes may occur. Often a headache will accompany a fever as well as increased thirst. Sometimes, dehydration may occur, a condition that can be much more dangerous than just having a fever alone.