Question Author
Thanks, Old Geezer and Woofgang for your suggestions. The lamp has chains to suspend it from the ceiling, so knocking it over is not a problem. The light bulb is glass, with a metal shade, and as it would be suspended it would not be vulnerable to splashes. One of the local animal sanctuaries used to use heat lamps but I am very uneasy about it and think, as you suggest, it might be a fire risk. I think I will have a look at the greenhouse heater - and thanks for your suggestion about the RCD plug, which I had to read up on, before I understood it. After all this, I intend to ask my friendly local spark for advice.