Some folks on occasion enjoy melting glass bottles over a fire. Although it’s not exactly the safest way to go about it, it can be done. The results, however, will likely not be what you had envisioned. I explain more in my article about slumping and draping, but for now know that while you can make simple items like spoon rests over a fire, the risk of the glass cracking or shattering is rather high because of the inability to precisely control the heating and cooling of the glass.