Among the earliest forms of healing, hydrotherapy could be considered primitive. Hydrotherapy is used to increase skin blood flow and warm tissues.
A hydrotherapy treatment involves the use of water in some way, but it is much more than water therapy. A regular component of this technique is the use of temperature variations of water that is used to direct healing in a certain direction or to a specific area of the body. It is much more dramatic and rapid to change the temperature of muscles by immersing them in hot or cold water than by using hot or cold packs. Also, changing the composition of the water can alter the outcome.