Fever

Fever and seizures Fever was described as a manifestation of disease in extant medical texts dating back to the sixth century BC. The authors of these works often incorporated fever into their theoretic frameworks of medicine; some, such as Hippocrates, came to understand fever as a defense mechanism against some forms of disease. Measuring body temperature came much later, and was firmly established in 1868 by Wunderlich. He demonstrated that body temperature varied throughout the day, and that there is a normal range in the general population of healthy people (Mackowiak 2010). Recent studies suggest that the majority of oral temperatures in normal subjects spans a range from 36 to 38 °C (97 to 100.4 °F). However, the study of clinical temperature abnormalities should be based on rectal temperature or other estimates of core temperature, such as blood, bladder, or esophageal temperature. These estimates are approximately 0.5 °C (1°F) higher than oral temperatures. The balance between heat generation and heat clearance is controlled by the hypothalamus; despite substantial study, the precise nuclei involved in temperature sensing and regulation remain debated. Blood temperature in the hypothalamus is the major afferent signal, but other inputs modulate this, including skin temperature on the cheeks and hands; warming these areas helps to prevent shivering during therapeutic attempts to lower temperature. The integration of these thermal inputs produces an estimate of core temperature. Hypothalamic nuclei provide a setpoint against which the sensed core temperature is compared, and they mediate thermoregulatory behaviors.