Heat exchange in men and women following intravenous injection of endotoxin

Abstract

An assessment was made of heat exchange during the course of an induced febrile episode following injection of endotoxin. Experiments were performed on either normal subjects or patients with recurrent fever. They were given intravenously either saline or a dose of 1 or 2 mμg Lipexal (the lipopolysaccharide of Salmonella abortus equi) per kilogram approximately 15 min before being exposed for 3–6 hr to 27.7 C air while wearing minimal clothing. Continuous measurements were made of: oxygen consumption, carbon dioxide production, core temperatures, skin temperatures, muscle surface temperature, and heat flow from the lateral surface of the upper and lower arm and the back of the hand. Three distinct patterns of reactivity were found: a) nonreactors (N = 2), b) those in whom elevated heat production preceded a rise in core temperature (N = 8), and c) those in whom thermal redistribution produced a rise in core temperature prior to an increase in heat production (N = 5). The results suggest that endotoxin may produce fever by alteration of either vasomotor control of heat redistribution or heat production at independent rates. Fever patients, in comparison to normal subjects, appeared to have an exaggerated metabolic response per equal increment in core temperatur Note (With the Technical Assistance of D. Thrasher) cold; fever; temperature regulation Submitted on December 23, 1963

Non-contact infrared assessment of human body temperature: The journal Temperature toolbox

“…The ETRS in focus and large enough to be easily discriminated from the background The ETRS is no larger than 10% of the size of subject's face (in a face only image) The ETRS is set to a temperature close to the threshold temperature (i.e., 35 devices represents the measurement area. As these devices will return a value which is the average temperature value over a given area, this introduces a source of error.…”

Modelling the Efficacy of Febrile Heating in Infected Endotherms

“…Across the scales from uncertainties as to how fever benefits an endotherm, there are clear costs. The most salient is energetic: fever is estimated to have an additional energetic cost of between 10 and 30% of basal metabolic rate in humans (Du Bois, 1921;Buskirk et al, 1964;Baracos et al, 1987;Benhariz et al, 1997).…”

Living history: Elsworth R. Buskirk

“…To learn whether patients with febrile episodes have abnormal thermoregulatory responses, Buskirk and colleagues measured changes in heat production, body temperatures, heat flow, and heat storage in normal and diseased subjects after intravenous injections of endotoxin (27). Subjects were classified as nonresponders, responders whose elevated heat production preceded an elevation in core temperature, and responders whose redistribution of heat resulted in an increase in core temperature before causing an increase in heat production.…”