<P> Perspiration is a sign of autonomic responses trying to cool the body . Users are advised to leave the sauna if the heat becomes unbearable, or if they feel faint or ill . Some saunas have a thermostat to adjust temperature, but management and other users expect to be consulted before changes are made . The sauna heater and rocks are very hot--one must stay well clear to avoid injury, particularly when water is poured on the sauna rocks, which creates an immediate blast of steam . Combustibles on or near the heater have been known to result in fire . Contact lenses dry out in the heat . Jewellery or anything metallic, including glasses, will get hot in the sauna and can cause discomfort or burning . </P> <P> Temperature on different parts of the body can be adjusted by shielding from the steam radiator with a towel . Shielding the face with a towel has been found to reduce the perception of heat . It may be advisable to put an additional towel or special cap on the hair to avoid dryness . Few people can sit directly in front of the heater without feeling too hot from radiant heat, but their overall body temperature may be insufficient . As the person's body is often the coolest object in a sauna room, steam will condense into water on the skin; this can be confused with perspiration . </P> <P> Cooling down is a part of the sauna cycle and is as important as the heating . Among users it is considered good practice to take a few moments after exiting a sauna before entering a cold plunge, and to enter a plunge pool by stepping into it gradually, rather than immediately immersing fully . In summer, a session is often started with a cold shower . Therapeutic sauna has been shown to aid adaptation, reduce stress hormones, lower blood pressure and improve cardiovascular conditions . </P> <P> Today there are a wide variety of sauna options . Heat sources include wood, electricity, gas and other more unconventional methods such as solar power . There are wet saunas, dry saunas, smoke saunas, and steam saunas . There are two main types of stoves: continuous heating and heat storage - type . Continuously heating stoves have a small heat capacity and can be heated up on a fast on - demand basis, whereas a heat storage stove has a large heat (stone) capacity and can take much longer to heat . </P>

What is the point of a dry sauna