Contrary to what one might think, the hot tub is not an early invention. Ancient civilizations used this kind of relaxation. Ancient tubs were a pool filled with water heated by volcanic lava or rocks and were a social meeting place. Rich people had their servants blow air through some curved tubes into their hot tub. A Jacuzzi is more than a luxurious accessory. Sitting in a Jacuzzi for a period of time has a number of benefits, both physical and mental.