Brown adipose tissue lipid is the main source of energy during arousal of the golden hamster (Mesocricetus auratus).

1. Male golden hamsters were induced to hibernate. 2. During stimulated arousal (i) the time course of increase in deep body temperature was related to the time-course of increasing oxygen consumption and (ii) brown adipose tissue lipid content was determined at several time points. 3. In early arousal (0-30 min) more lipid was mobilised (14.6 kJ) than was utilised in metabolism (3.5 kJ). BAT lipids accounted for 88% of the total energy requirement of arousal (90 min). 4. We conclude that BAT not only supplies heat for arousal but fuel for other arousing tissues.