I know the lack of climate control is not good for machines and the cabinets. Hot attics are also not helpful. If you can bring them inside, do so. I've seen melted bobbin winder tires, cracks in belts and the same cracked bobbin winder tires from hot attics and the cold and then quick warming wouldn't be good for veneer wood. As a test, I put a new bobbin winder tire on a parts machine and stuck it in my hot attic over the summer. I removed it after only a few months and the new bobbin tire was all cracked and useless. I would also believe any machines with nylon parts or cams would also be affected. I often wonder if many of the cracks we see in these gears and parts are because they were stored in cold areas.