An electrician must be able to layout, assemble, install, repair, and test entire electrical and electronic systems. Along with their electrical training, journeymen electricians must have a complete working knowledge of blueprint reading and know the national electric code as well as local codes. There is of course the hazard of electrical shock and burns from "live" wires; therefore, safe work practice is a must. Electricians must be mechanically inclined, physically fit, and enjoy working with mathematical formulas. Electrical work is performed both indoors and outdoors in all temperatures and weather conditions.