If you're on fire, stop drop and roll but not if you're a square-shaped being. lMAO. Maybe start the flames at the sides of his/her body, so you avoid the bad hair jokes. The top of any character will be considered the head and anything on top of it is therefore its hair. I like the fire, it's consistent with the drawing style and will probably be readily recognized as fire with an off-the-head placement. I might lose the stop sign because it has other meanings that are not related to your story here. I'd also lose the arrow, you don't need. And I might change help to "uh, oh!" but that's just me.
Anyway, very original style, nice idea, well done!
this is cool.. but if it were on a shirt.. i thnk the text might have to be a bit bigger. also the characters could be larger. maybe spaced closer together..
and if people are still confusing the fire with hair.. maybe get some smoke coming from the fire.
That orange shading went a long way. I think "Help" could be changed to something else. I'm feeling uncreative right now, but play around with some other words, like, "panic," or something like that.