Adrenergic, coagulation, and fibrinolytic responses to heat.

Two groups of volunteers were exposed to heat in a sauna bath-one group for 10 minutes and the other for 15. There was no change in plasma adrenaline concentration until the subjects emerged from the sauna bath, when there was a slight increase in concentration. Factor VIII and thrombo-elastograph patterns did not change but marked activation of fibrinolysis was stimulated by exposure to heat. These findings support the concept that fibrinolysis is not mediated by direct adrenergic activity.