An example of hydrotherapy is:

• A. Whirlpool
• B. Sauna
• C. Cold pack
• D. Ultrasound

Answer: (A)

Hydrotherapy uses water to produce therapeutic effects through immersion, buoyancy, hydrostatic pressure, and temperature changes. A whirlpool fits this category because it involves immersing the body part in circulating water with jets, combining the soothing or cooling/heating effects with mechanical massage from the water flow and the pressure of the water around the tissues. This combination of immersion and water movement is what defines hydrotherapy. In contrast, a sauna delivers heat through air (often with steam) rather than water immersion, so it isn’t hydrotherapy. A cold pack provides localized cold without immersion in water, and ultrasound is a deep-heating modality that uses sound waves with gel or direct contact rather than water-based immersion.