Populations of widely distributed ectotherms demonstrate different cold resistance corresponding to the local climate. However, efficiently thermoregulating ectotherms could avoid divergence in cold resistance. Two species of ants, previously shown to even out latitudinal differences of mean summer temperatures in their nests, were used to test this hypothesis by comparing the temperature depen...

Despite some evidence of within-population phenotypic variation in fish thermal behaviour, the occurrence of alternative tactics of this behaviour is rarely explicitly considered when studying natural populations. Brook charr provide an example of within-population variability in behavioural thermoregulation as revealed by a recent study on a lacustrine population of this species. The objective...

BACKGROUND AND OBJECTIVES Hypothermia contributes to neonatal mortality and morbidity, especially in preterm and low birth weight infants in developing countries. Plastic bags covering the trunk and extremities of very low birth weight infants reduces hypothermia. This technique has not been studied in larger infants or in many resource-limited settings. The objective was to determine if placin...

Core body temperature is normally tightly regulated to within a few tenths of a degree. The major thermoregulatory defences in humans are sweating, arteriovenous shunt vasoconstriction, and shivering. The core temperature triggering each response defines its activation threshold. General anaesthetics greatly impair thermoregulation, synchronously reducing the thresholds for vasoconstriction and...

427 serpentina) during summer. Can. J. Zool. 68:1659–1663. caSe, t. J. 1972. Thermoregulation and evaporative cooling in the chuckwalla, Sauromalus obesus. Copeia 1972:145–150. cHriStian, k. a., c. r. tracY, and c. r. tracY. 2006. Evaluating thermoregulation in reptiles: an appropriate null model. Am. Nat. 168:421–430. congdon, J. d. 1989. Proximate and evolutionary constraints on energy relati...