Get tough little onions! You're staying outside from now on! This cold frame was made just for you. The window frames came from an old nursery business (thanks to craigslist). The people I bought them from called them "hot bed" frames, as in "cold frames" heated with fresh manure. No added heat here - just a miniature greenhouse where the seedlings can hang out until we put up the hoophouse. All the parts are here, see?