I know I have seen on here a dozen times how to build a heater with a light bulb and a cement block, to set your metal waterer on. For some reason, I now can't locate any of these posts. I remember most of the basics, but on thinking about doing it, how do you keep the bulb from setting the wood floor, or the pine shavings on fire? In other words how do you make it safe? Can anyone more skilled at finding stuff than I am give me some of these posts, or describe how you do it? Thanks.