Systemic responses in man exposed to different heating and cooling treatment in a sauna.

Finnish saunas are popular for alleviating psycho-emotional and physical stress. Regular visits to a sauna may promote three adaptive effects: a simulation of the training generally associated with sports activities, the building up of resistance to the effects of extreme exposures, and the regulation of autonomic functions. However, the effect that the sauna has on the physiological mechanisms of humans--particularly, the effect of contrast-cooling following thermal exposure--is still obscure. An example of contrast-cooling following thermal exposure is that caused by swimming after using a sauna; such contrast-cooling may be a risk factor for people with unstable blood pressure, and gradual cooling-off after using a sauna may be preferable. In this series, various autonomic functions under different heating and cooling treatment in a sauna were studied. The authors have concluded that the mode of exposures to heating and cooling under control of Heart Rate (HR) changes has, to a certain extent, a relaxing effect, and thus can be recommended for alleviating psycho-emotional stress.