I experienced something like this with my son once, I believe.
I have a stupid phobia of needles. I hate this phobia, because it makes me feel like a freaking weakling. The last several times I've had blood drawn, I passed out - cold.
My son is autistic, and needs to be sedated when I take him to the dentist. Once I made the mistake of watching the anesthesiologist put an IV in my son's arm (he was already quite tranqed). And I started getting that same freaking feeling like I was going to pass out, which starts with my limbs going numb. I didn't actually pass out, but I did have to go into the bathroom there, close the door, and sit on the floor for about 20 minutes taking deep breaths.
I'm not sure how well this qualifies with what you're describing. It may have more to do with my stupid needle phobia. But generally speaking, I don't have that much of a problem with watching other people get poked; I suspect in the case that I described, a strong sympathetic connection was an element in what happened to me.
Good fortune,
- Icarus will invent a functional hypo spray...
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