Electric-powered mowers and other tools should not be used in the rain, on wet grass or in wet conditions. Inspect power tools and electric lawn mowers before each use for frayed power cords, broken plugs, and cracked or broken housings. If damaged, stop using it immediately. Repair it or replace it. Always use an extension cord marked for outdoor use and rated for the power needs of your tools. Remember to unplug all portable power tools when not in use. Since metal ladders conduct electricity, watch out for overhead wires and power lines.