Figure 2. Progressive reduction in core temperature did not trigger an increase in oxygen consumption (V^O2) that may indicate nonshivering thermogenesis. Instead, hypothermia decreased systemic oxygen consumption. V^O2= 0.83 (core temperature)=-23.3 degrees Celsius; r²= 0.92. Intraoperative plasma norepinephrine concentrations were variable but did not change significantly as a function of core temperature. Data are presented as means +/- SD.