Why would my face feel on fire and bad back pain?

Fever? Infection? Check your temperature, you may have fever. If you have fever and back pain you need to get seen right away to be sure you don't have a serious infection, like a kidney infection. If no fever, and your problems have been present for weeks or months, get seen soon and find out what is going on exactly. We don't have enough information to give a more specific answer. Get checked!