elaxing in a hot tub or sauna may feel great after a workout or a long day. But take steps not to become dehydrated when you use one. Prolonged exposure to the high temperatures causes you to sweat, which depletes the water level in your body. When this happens, an increased heart rate, headache, cramps, dizziness or confusion may result. The heat also dilates blood vessels and may cause a dangerous drop in blood pressure. If you enjoy the sauna or hot tub, drink fluids (not alcohol) before, during and afterward. And limit your exposure to the hot temperatures to fewer than 15 minutes. Also, stand up slowly, and exit the tub carefully. If your blood pressure drops, it's easy to pass out. If you take blood pressure or heart medicine, ask your doctor if it's safe for you to use the sauna or hot tub. Other medicines also may make you susceptible to a dangerous drop in blood pressure, so make sure they're safe before you take a dip. © Your HealthStyle, 1999.