Thermal changes observed before and after J.-L. Etienne's journey to the North Pole

Abstract
The thermoregulatory responses of a French doctor, Jean-Louis Etienne, were examined in a standard cold test before and after his journey to the North Pole, to investigate whether general and/or local cold adaptation had occurred. The two tests were carried out in a climatic chamber for 2 h at rest (dry bulb temperature, 1° C; relative humidity, 40%; wind speed, 0.8 m · s−1). After his journey, Etienne showed a general hypothermic-hypometabolic adaptation, i.e. a decrease in rectal temperature (T re) and metabolic heat production (M), and an increased local skin temperature of the extremities. Between the two tests, a change occurred in the relationship between tympanic temperature (T ty) and M. During the post-journey cold test, T ty [as representative of the central nervous system (CNS) temperature] increased while the decrease in T re was accelerated, probably due to a redistribution of blood volume towards the CNS. Such a mechanism would protect the central core with special reference to the CNS.