My old garage was not heated. I kept any electronics and paints inside the house. My large power tools were left outside during the winter months and never rusted. If I needed to get some work done out there, I fired up the kerosene heater for a couple of hours hour to warm the equipment up, and was able work. I insulated the garage and installed a propane heater which was really nice because I could leave all my equipment in there year round. My garage burnt down (not because of the heater). My new garage is fully insulated, electric heat, and is kept at a nice 64 degrees. you need to insulate the building before using a permanent heat source. Or you can fire up a portable heater to get equipment warmed up before operating.
