A 120V male-to-male extension cord would be dangerous because that house circuit it gets plugged into is likely designed for 15A Max, would overheat if too much draw from everything connected within the house. On the other hand, a 240V male-to-male range cord could handle ~50A and be a much safer solution, though dryers, ranges, water pumps, big AC becomes a tremendous load on top of 120V appliances connected. Dryer cords are usually rated for 30A.