Figure 40-20 Total cutaneous heat loss when the volunteers were covered with a single warmed (open circles) or unwarmed blanket (open squares) or three warmed (filled circles) or unwarmed (filled squares) blankets. These data indicate that warming cotton blankets is of little benefit and that adding additional blankets only slightly decreases cutaneous heat loss. Data are presented as means ± SD. (Redrawn from Sessler DI, Schroeder M: Heat loss in humans covered with cotton hospital blankets. Anesth Analg 77:73–77, 1993.)