Are these OK for batroom use? My Mums bathroom is very cold at the moment (obviously). She is toying with the idea of a De Longhi radiator with a hole drilled through the wall and plugged into a socket on the landing. If I cut the plug off and drill a hole for the cable and re attach the plug will it be safe using the rad in this situation. I was thinking of shortening the cable so there would be no chance of it finding it's way into the bath.