My Mother's first rule of life was "Nothing is so worthless it should ever be thrown away." She passed away in '92 and we are still tring to get all her posesssions dealt with. However. I did not throw away a crockpot that I had that had developed a hairline crack in the ceramic vessel. It wasn't unstable or anything but I did not want to trust it with liquids. We filled the pot with good sized (1") washed dry gravel put the lid on and fired it up in the chicken house. A little away from the wall in in the walkway away from litter. Also we put it on an aluminum cookie sheet (a wellworn, damaged Air Bake -See I am like my Mother, I never throw anything away either) more to refelect the radiant enegy away from the floor than for any other reason. Aluminum is a great reflector of radiant energy. I am very confident in the safety of this apparatus. And we had a crock pot at work for 5 years that ran 4 hours a day five days a week so I expect this heater to last a long time. We plan on using the "off", the "hi" 275W and "lo" 200W settings to adjust the heater through out the winter depending on the weather forecast. You could also use a timer or a thermostat. Remember that the gravel, once it is warm, will radiate heat for several hours. I sell heat lamps by the thousands and I can assure you that the physics dictate that this crockpot heater is far more efficient than a light bulb for heating air.