DS played paintball at a birthday party and got shot on the adam's apple. It was a freak accident and he was fine, but it scared him a lot because he had some breathing issues at first, in addition to the pain. His mask should have covered his neck, but I think he was looking up.
I'm just glad I decided to stay for the party--I had planned on signing him in and leaving. All the waivers made the mommy in me nervous, though, so I stayed. He enjoys shooting guns, but that gave him a healthy respect for them, and now he says that even with paintball, he'd rather shoot at cans (like he does with his BB gun) because he wouldn't ever want to hurt another kid like he got hurt.
Not that anything like that is likely to happen, but wear your mask and make sure your neck is covered by it.