When we're teaching people about fire safety at the Temple, we talk about the conditions to assess weather or not the dancer is in the proper space to spin fire in. I break down the "self check" into three questions that I call the "3 C's":
Are you Clear? That is, do you feel mentally alert enough to be burning fire? Things that might impact this answer are your mood, how hard a day you had, how much you've been working, a fight you had with someone, an emotional event in your life, and your use of altering substances including alcohol.
Are you Capable? That is, do you feel physically capable of doing the dancing you're attempting to do? Things that impact this answer include how much exercise you have done, how many times you have already burned recently, your use of altering substances, and how tired you are. BEWARE of the adrenaline rush! It can deceive you both on a mental and physical level. My friend Rob stopped my from doing a third burn one night when I was more tired than I realize and hyper pumped because of the adrenaline.
Are you Competent? That is, are you doing moves that you are trained and practiced in? At some point in time, each move will have its "first" time with fire and no matter how much you practice without fire, it isn't necessarily the same feeling with the fire there. I prefer, if I am trying moves that are still wild and not fully practiced, to be extra careful with my hair and ensure my head is covered (even though I usually spin without); hair really is the quickest to burn away.
Read more about fire safety here.