Behavioral thermoregulation in the squirrel monkey: Adaptation processes during prolonged microwave exposure

Investigated exposure duration at power densities above and below the threshold of 6-8 mW/cm² with 2 male monkeys. Ss were restrained in the far field of a horn antenna inside an anechoic chamber heated and cooled by forced convection. Ss learned to control the temperature of the circulating chamber air by selecting between cold and warm air sources. Ss were exposed to 12.4-cm (2450-MHz) continuous-wave microwaves for periods from 5 to 150 min. Microwave power densities explored were 4, 10, and 20 mW/cm². The 4 mW/cm² microwave exposure did not modify thermoregulatory behavior. The 10 and 20 mW/cm² exposures stimulated the monkeys to select ambient temperatures 1.5 and 3.0°C cooler than control levels, respectively. Except during the early minutes of an exposure, duration had no significant effect on selection of air temperature or on the body temperatures thereby achieved. (25 ref)