ABSTRACT
Body temperature, normally 36–37.5°C, is controlled by the thermoregulatory centre in the hypothalamus, responding to central and peripheral thermoreceptors. The American Society of Critical Care Physicians defines clinically significant temperatures as greater than 38.3°C, although hypermetabolism can cause severe hyperpyrexia. Malignant hyperpyrexia, a genetic disorder of calcium channels in skeletal muscle, may be triggered by drugs and stress. Historically, temperature measurement was usually oral, rectal or axillary, often with mercury-in-glass thermometers. Problems from hypothermia include: reduced dissociation of oxygen from haemoglobin, peripheral shutdown, causing anaerobic metabolism, cardiac dysrhythmias, and hyperglycaemia. The term "targeted temperature management" has been coined to include therapeutic hypothermia, and maintenance of normothermia. Hypothermia reduces metabolism, so reducing cerebral oxygen demand and reperfusion injury. Non-invasive skin probes, usually on patients' feet, measures peripheral temperature.
