Fever is an innate immune response characterized by an abnormally high body temperature, specifically above 37.8 degrees Celsius (100 degrees Fahrenheit). This physiological change is part of the body's second line of defense against infections, aimed at eliminating microbes. The hypothalamus, a region in the brain, acts as the body's temperature-regulating center, maintaining normal body temperature around 37 degrees Celsius (98 degrees Fahrenheit).
Elevated body temperatures associated with fever can inhibit the growth of most bacteria, serving as a protective mechanism against infections. Additionally, fever enhances the body's protective functions by increasing the rates of enzymatic reactions, which in turn boosts the inflammatory response and the release of inflammatory cytokines. These cytokines play a crucial role in fighting off pathogens more effectively during a fever.
The term pyrogens refers to substances that induce fever. They can be classified as endogenous pyrogens, produced within the body, or exogenous pyrogens, originating from external sources. Understanding the role of pyrogens is essential in recognizing how the body responds to infections.
In summary, while a fever may cause discomfort, it is a vital response that aids in the elimination of microbes and enhances the immune system's effectiveness. This innate effector action is a key component of the body's defense mechanisms, illustrating the complex interplay between temperature regulation and immune response.