Fever

Every one of us has experienced the wave of chills and exhaustion that a fever causes. Fever usually occurs in response to an infection as with the flu or cold viruses or strep throat bacterial infection, or with inflammation that occurs with tissue injury or disease (such as with some cancers). However, many other causes of fever are possible, including drugs, poisons, heat exposure, injuries or abnormalities to the brain, or disease of the endocrine (hormonal or glandular) system.

A fever rarely comes without other symptoms. It is often accompanied by specific complaints, which may help to identify the illness causing the fever. This can help the doctor determine which treatment is necessary.

Normal body temperature can vary depending on the individual, the time of day, and even the weather. For most people, a temperature of 98.6 F (Fahrenheit) (37 C or Celsius) is baseline.

Temperature is usually controlled by the part of the brain called the hypothalamus.Fever occurs when the body's immune response is triggered by pyrogens (fever-producing substances). Pyrogens usually come from a source outside the body and, in turn, stimulate the production of additional pyrogens inside the body. Pyrogens tell the hypothalamus to increase the temperature set point. In response, our body begins to shiver; our blood vessels constrict (close); we get under the covers in an attempt to reach the new temperature that is higher than our baseline. However, other pyrogens can be produced by the body, usually in response to inflammation; these are referred to as cytokines