INTRODUCTIONThe effect of temperature on the action of drugs in animals and man has interested physiologists and pharmacologists for a long time. Several review articles have appeared in the last 25 years. In some, the effects of body temperature (22,38,92) were differentiated from those of environmental temperature (40, 90) on drug action. The effects of climate were considered by K. 1. Furman (41) and Weihe (111). F. A. Fuhrman (39) and K. 1. Furman (42) reported on the effects of heat, and Johnson (66) on the effects of cold. A different approach to the problem dealing exclusively with the sensitivity of laboratory animals is pre sented in the reviews by Laroche (75) and Ellis (34). All these reviews deal chiefly with experiments on animals which demonstrated striking effects of heat and cold on drug toxicity.Many proceedings of symposia and review articles have been published since 1960 on the mechanism of temperature regulation and the physiological effects of heat and cold (13,33,51,52,55,76,94) and on temperature regulation and drugs (77,83,108,109). In the same period, publications dealing with the specific problems of alteration of drug action by temperature or climate in man are rare (39,41).Most inVestigations on the modification of drug action were done with com mon homeothermic laboratory animals. They demonstrate either a variation of results in drug testing due to an improperly controlled thermal environment, or a change of sensitivity of the animal to drugs under controlled conditions of heat and cold. New problems have arisen from toxic effects of environment pollution in various climatic zones. Here, too, little has been published as yet. This paper will deal only with homeothermic species not subjected to induced hypo-or hyperthermia.THERMOREGULATION Normally, homeothermic species show a very small variation of core tempera ture within 24 hours. On exposure to extreme heat (> T. 33°C) and cold « T. 15°C) mice and rats maintain their body temperatures by means of powerful 1 Parts of this review were presented at the Symposium on the Pharmacology of Thermoregulation, San Francisco, 29-31 July 1972, and are published under the title .. The effect of temperature on the action of drugs" in .. The Pharmacology of thermoregulation" edited by P. Lomax and E. Schonbaum, Karger, Basel, 1973. 409 Annu. Rev. Pharmacol. 1973.13:409-425. Downloaded from www.annualreviews.org Access provided by Chinese University of Hong Kong on 02/05/15. For personal use only. Quick links to online content Further ANNUAL REVIEWS 410 WEIHE homeostatic mechanisms. In mice, Chen et al (17) measured at an ambient tem perature (T.) of 20°C a rectal temperature (T ro) of 34.7°C and at T a 4O°C a T ro of 38SC. Doss & Ohnesorge (30) found in mice after ISO min at T. 3SDC a T,. 38.4OC and at T. 30DC aT,. 36.8°C. At T. ISoC the T .. was 36.6°C. Usinger (106) working with 30DC adapted resting mice, recorded a decrease of Tre from 35.60 to 35.1 DC after a change to T. 20°C. In rats, Maickel (79) measured after a 4-hr exposure at ...