* Fever is a complex physiological reaction to disease involving a cytokine (proteins that either stimulate or inhibit immune-system function) that triggers a rise in core body temperature along with activation of various metabolic, endocrine and immunological systems (Arch Intern Med, 1998; 158: 1870-81).
* Fever is the regulation of body temperature as a response to infection.
* Fever can be induced by a variety of agents, including bacteria, viruses and fungi. In response to these agents, the body produces a pyrogen (proteins produced by immune system white blood cells), believed to be the cause of a raised temperature (Pediatrics, 1980, 66: 720-4).
* A raised temperature is simply one component of what is essentially a multifaceted response to infection.
* A raised temperature does not necessarily mean a fever. Body temperature can be affected by a warm environment, exercise or eating (Arch Intern Med, 1998; 158: 1870-81).
* At rest, more than half the body's heat is generated as a result of a biochemical inefficiency in converting food into energy (Arch Intern Med, 1998; 158: 1870-81).