We studied the effects of orengedokuto on central hyperthermia after mild hypothermia therapy for cardiac arrest. The subjects in this study were 7 patients who showed central hyperthermia (>38.3 °C) after mild hypothermia therapy. Orengedokuto 7.5-15 g/day was administered and central temperature was monitored. Maximum change in central temperature was 1.55 ± 0.71 °C(from 39.1 ± 0.7 °C to 37.6 ± 0.7 °C) (p < 0.05). Mean change was 0.35 ± 0.77 °C, (from 37.7 ± 0.6 °C to 37.5 ± 0.7 °C). Thus we conclude that orengedokuto is a drug with applications in the treatment of central hyperthermia after mild hypothermia therapy.