Mullington CJ, et al. - Researchers investigated if converting epidural analgesia (for labor) to epidural anesthesia (for emergency caesarean section) blocks active cutaneous vasodilation (cutaneous heat loss and skin blood flow decrease), and as a result, increases mean body temperature. Participants were 20 women in established labor. After epidural top-up, chest and forearm heat loss decreased, but head, thigh and calf heat loss remained the same. The mean decrease in heat loss was 15 (19)%. Following epidural top-up, no change in either arm or thigh skin blood flow was noted. The reduction in heat loss and the increase in mean body temperature, despite no change in skin blood flow, could most probably be due to blockade of active cutaneous vasodilation. A similar mechanism could be responsible for the hyperthermia associated with labor epidural analgesia.