Fever: mechanisms and symptomatic treatment

[Extract] Body temperature is regulated around a set point by the preoptic area (POA) of the anterior hypothalamus, which acts to balance heat loss via the periphery against heat production by the tissues. The POA contains neurons that integrate information from ascending pathways originating from skin and visceral thermoreceptors and from endogenous signals in the cerebrospinal fluid (CFS). The level of activity of these neurons results in either sympathetically-mediated heat-loss or heat-gain responses. Heat is lost through peripheral vasoclilaration and sweating, and heat production is limited by reduction of physical activity. Heat is conserved through peripheral vasoconstriction (central shunting), piloerection and chills, and warmth-seeking behaviour (such as putting on warmer clothes or seeking a warmer environment). Heat production is increased through shivering, as well as through the release of thyroid hormones, glucocorticoids and catecholamines.