This happened to me the first time I smoked out of a bong. Noone explained to me how to do it and I just did what I thought I was supposed to do and took two MASSIVE hits, one after the other. I got really scared, and started shaking uncontrollably. I was sititng by the door, which was opening and closing a lot so the cold weather probably had a lot to do with it. My vision got really blured/stretched at the edges and I was convinced that I was going to die. At first, I thought it might have been laced with salvia or something, but my friends seemed fine. I ask them if what was happening to me was normal (by this point, I was delusional) and what was going on, shaking the whole time. By then, my friends were pretty worried and after a lot of pleading from me, I convinced one of my friends to drop me off in front of the emergency room. He did, but I guess it wasn't the ER because wherever he dropped me off (I don't remember much from this point), the door was locked. I wondered around and eventually found myself in the ER waiting room. All I remember was flopping down in a waiting chair and blacking in and out of being awake. I remember talking to someone, about the time, but don't remember what he or I said. Eventually, I completly pass out, wake up after an hour or so (by now, almost three hours have passed since I took the hits) and I felt A LOT better, so I walk back to my dorm and pass out. Felt kinda ****** the next day but it passed. Swore I wouldn't smoke again for a really long time, but that wasn't true