On New Years Eve 1973, Kiss played Academy Of Music, New York. During the fire breathing at end of “Firehouse”, Gene Simmons unwillingly set his hair on fire for the first time (of many).

Photo: Bill Green shot this photo seconds before Gene set his hair on fire for the first time.

Dale Sherman:
“Finally, the band got to “Firehouse” and Gene prepared to do his fire breathing stunt. Holding the torch up in the air, Gene managed to spit out a flame that shot straight up into the air. The audience went nuts and Gene stood before the audience, proud of his ability to excite them. It was then that a roadie for the band ran on stage and wrapped Gene’s head in his jacket, smothering the fire that was raging through Gene’s hair. Caught up in the moment, Gene had not even realized that it had occurred and was surprised when he found himself on the floor with a jacket over his head. It occurred to him later that the audience was not actually cheering him pulling off the fire breathing effect as much as cheering him, they assumed, knowingly setting himself on fire.”
– “Black Diamond: The unauthorized biography of Kiss” by Dale Sherman

Gene Simmons:
“By the third song, “Firehouse,” the stage was covered by fog. Sirens were going off, flashing lights were blinding people, and the entire place was on its feet, fists pumping in the air. And if they thought they had seen it all, we would give them more. I emerged from the fog in full KISS gear, carrying a sword with the hilt lit on fire and my mouth full of kerosene. I came to center stage and I spit out the kerosene. A huge ball of fire erupted out of my mouth, and the audience went nuts. I stood there, legs spread apart, soaking in the adulation. It was then that I smelled something burning. I had wanted to look extra cool on our opening night, so I sprayed extra hair spray on my hair so it would really puff out. Sean Delaney ran out and wrapped my head in a wet towel, and they went out of their minds! We came. We saw. And we damn well conquered. We were the sensation of the show, and a few weeks later, when a British magazine called Sounds published a New Year’s roundup of shows across the world, they printed a picture of me.”
– “Kiss and make-up” by Gene Simmons

Gene Simmons tells the story of that day: