• A hydro collator is a stationary or mobile stainless-steel thermostatically controlled liquid heating device designed to heat bentonite filled packs in water up to 160 degrees where the packs will be removed and wrapped in several layers of towelling and applied to the affected body area of patient to relieve acute pain or relax certain muscle groups. • Moist heat therapy applied to the surface of the skin enlarges blood vessels below the surface, relaxing tissue and relieve painful symptoms. • It is recommended for relaxation of tissue in chronic spasm and relieves the chronic pain and tightness • Benefits helps increase circulation, relaxes muscle tension, reduces it stiffness and prepare tissue for rehabilitation • It is commonly used in muscle strain and ligament sprain • Moist heat has a more sedative effect than dry heat