Back in the 70's there was a professor at Cleveland State U. that was noted for demonstrations, open to the public, to advance interests in physics. He had laser shows, sonic demonstrations, and once a year, walk on coals. I think one year he got a slight (second degree?) burn on a toe, but that was the extent of the damage over a several year period (at least.)

I can't remember his name, but I saw a couple of his demos. I went to Case instead of CSU so I didn't take his courses, but they probably would have been interesting. He was a good speaker, very organized, and quite passionate about his field.