Pyrexia and temperature control

Human bodies can only function healthily within narrow temperature ranges. Body temperature, normally 35-37C, is controlled by the thermoregulatory centre in the hypothalamus, responding to central and peripheral thermoreceptors. If cold, vasoconstriction and shivering responses conserve and produce heat; if hot, sweating and vasodilatation responses increase heat loss. Body temperature normally varies up to 0.5C during each day (Weller, 2001).