Since it's usually cold in the garage, I keep the block in our mud/laundry room, which is always warm because A), it has a heat vent, and B) the wife is always washing/drying clothes.
So I take it out in the garage, paint with lacquer, and bring it right back into the laundry room and hang it there.
Back and forth for a few coats then the clear, then it hangs in the laundry room for a day, and it's ready.