Spinal anaesthesia is the gold standard for elective caesarean section. This technique presents several adverse effects. We report a severe case of hypothermia (33.3 degrees C) after spinal administration of bupivacaine (10 mg) and morphine (100 microg) for elective caesarean section. After excluding other causes of hypothermia, this one could be explained by both the own effects of local anaesthesia (i.e. peripheral vasodilatation) and by the central effect of intrathecal morphine. Because hypothermia is not predictable after spinal injection of morphine both monitoring of central temperature and active warming of the patients could be proposed. Naloxone has been proposed in a case of hypothermia related to spinal injection of morphine.