I have a heat lamp that I'm setting up with a terrarium to keep some plants warm enough to be in the terrarium rather than in a different room. The only problem is that on a warmer day the sun comes in and warms it up by itself, so when I was testing the light today it was 87 degrees at four thirty in the afternoon, which is a bit on the hot side and it was undoubtedly hotter during the day. Does anyone know anything I can hook the power cord into that will turn it off when the temperature gets to be about eighty five or so?