Physical therapists treat disease, injury, or loss of a bodily part by physical means, such as the application of light, heat, cold, water, electricity, massage and exercise. They develop treatment plans based upon each patient's strengths, weaknesses, range of motion and ability to function. Physical therapy is a health care field concerned primarily with the treatment of disorders with physical agents and methods, such as massage, manipulation, therapeutic exercises, cold, heat (including short-wave, microwave, and ultrasonic diathermy), hydrotherapy, electric stimulation and light to assist in rehabilitating patients and in restoring normal function after an illness or injury.