Figure 3. Heat content of the arms and legs increased at virtually the same rate during forced-air warming with the heater set at “medium” and “high.” The increase in the legs was three times as great in the arms. With the heater set on “high,” total (arm and leg) heat content increased [nearly equal] 69 kcal during the first 30 min of warming and [nearly equal] 136 kcal during the first hour of warming, representing 38% and 75%, respectively, of the values observed after 2 h of warming. Elapsed time zero identifies the beginning of forced-air warming. *Value differs significantly from time zero.