An effect of injury on thermoregulation in man

The effect of trauma on human thermoregulation has been studied using a behavioural test and the vascular response to cold exposure. It was confirmed, in controls, that a pleasurable temperature for the hand (Thand) depended on core temperature (Tc) to which it was negatively related. Shortly after moderately severe fractures in a leg this relationship was lost and in the patients the slope of this regression line was not significantly different from zero and they usually chose a Thand towards the upper end of the normal range irrespective of Tc. This effect was not imitated in controls by removing 500 ml blood but Thand was increased by occluding the circulation to one leg. Naloxone did not alter Thand in controls but when given in a suitable dose it reduced the rise in Thand during a short period of limb ischaemia. Immersing one hand and forearm in water at 17 degrees C reduced the blood flow through the contralateral forearm and hand. The reduction in flow was positively related to the initial rate of flow in both controls and injured but the slope of the regression line was significantly less after injury. It is concluded that thermoregulation is affected by trauma in man.