Stress-induced rise of body temperature in rats is the same in warm and cool environments

Several forms of psychological stress result in a rise in body temperature in rats. In this study, we report that rats housed at a low ambient temperature (11.1 degrees C) develop stress-induced rises in body temperature that do not differ from the responses seen when the animals are kept at a temperature within their thermoneutral zone (24.7 degrees C). These data support the hypothesis that stress-induced "hyperthermia" is a regulated rise in temperature (i.e., a rise in thermoregulatory "set-point," or fever), and is not simply the result of metabolic changes associated with the stress response itself.