This happens to me and also my 15-year-old daughter, and I wonder if it's genetic because it started with her when she was only four-years-old, and she didn't know that it happens to me. She is triggered more easily than me; she daughter can't even read a book about someone getting cut without it happening. For me, it's only happened due to my own medical treatment. I get hot and start sweating, and then turn cold but am still covered with sweat. I've never passed out but have come close. I always have to lay down, though.

@annbainbridge what triggers your husband?