To the professional beauty therapist a fundamental knowledge of electricity is essential. The range and variety of electrical equipment is so vast that it is impossible to keep track of the latest piece, but the basic principles of working retain the same for each type of current used. Galvanic, faradic, sinusoidal and highfrequency currents are those most commonly utilized for cosmetic purposes, although the direct current is little used today. Together with radiant heat, infra-red and ultra-violet radiation, they provide some of the many methods of treatment that therapists will be required to employ during their career. Both in electrotherapy and actinotherapy the highest level of skill, attention and care in use of machines is required to produce good results and legitimate effects safely. This basic knowledge of the currents being employed and the effects on the tissues of the body cannot be learned overnight, or with the manufacturer's instructions in one hand and the client in the other. There are several dangers resulting from poor technique, inexperience and inadequate knowledge which can be fatal and crippling for life. A doctor should always be consulted before electrical treatments are commenced, however well qualified the therapist is.