The body temperature, Tb (A), resting metabolic rate, RMR (B) and NE-stimulated thermogenesis, NeST (C), and BAT mass (D), mitochondrial protein content (E) and COX activity (F) of Swiss mice exposed to a range of ambient temperatures from 5 to 35 °C. The X axis in panels A,D,E,F is the ambient temperature at which the animals were housed and measured. For panels B and C, the temperature refers to the housing temperature only. RMR (panel B) was measured at a fixed temperature of 30 °C, and NeST (panel C) was measured at a fixed temperature of 25 °C. Each point represents a different individual. ∗∗, significant effect of ambient temperature (P < 0.01).