A hot tub in the backyard is more than an investment in your home and family. It’s also an investment in your health. Designing Spaces meets with Richard Gottwald, president and chief executive officer of The Association of Pool and Spa Professionals.  He describes how hot tubs can relieve aches and pains such as back pain, knee pain, high blood pressure, and can also help with diabetes. Maurizio Vozza, president and CEO of Nordic Hot Tubs, defines hydrotherapy and its benefits. Nordic Hot Tubs use the Dual Therapy System (DTS) to combine variable water jets with whirlpool therapy to produce full-body massages.