do this with or without a flame, either way it is an unexpected surprise that delights.
without
a flame/lighter, I talk about how hot air rises, ask that they think of their card getting red hot
and rising to the top, I then touch their chosen card which has been forced to the top, pretend the
card burned my hand, tell them they did too good a job or making their card hot, reveal the blisters
then the card.
weird and wonderful