Figure 40-1 There is a linear relationship between mean skin temperature and the core temperature triggering vasoconstriction and shivering. Skin temperature contributes about 20% to control of each thermoregulatory defense. (Redrawn from Cheng C, Matsukawa T, Sessler DI, et al: Increasing mean skin temperature linearly reduces the core-temperature thresholds for vasoconstriction and shivering in humans. Anesthesiology 82:1160–1168, 1995.)