Figure 2. Circles identify the gain of shivering, as determined by electromyography, of the upper body (pectoralis, trapezius) and lower body (rectus abdominis, quadriceps femoris) without (control) and with epidural anesthesia. Squares show the mean values (+/- SD). Lower-body gain was reduced from -0.73 +/- 0.85 to -0.04 +/- 0.06 intensity units/[degree sign] Celsius during epidural anesthesia because of the paralysis of the lower body (P < 0.01). However, there was no compensatory increase in upper-body gain during epidural anesthesia.