Sophie from West Lincoln High school in Lincolnton NC was on my senior model team and I worked with her for over a year on many different shoots.  Her senior session was one that will go down in the books.  Its one that I talk about still to this day and mention it to every senior I work with.  Im talking about the time that Sophie passed out in her session.  We had been shooting for an hour or so and we were outside in the backlot of my studio at the greenhouse set.  She hadn't been drinking enough water.  I didnt know that at the time though.  I was setting up the shot and she suddenly became lethargic.  I had her positioned just where I needed her for the shot and she moved forward.  I was just about to say "no I need you to back up a little" when she just fell completely forward and literally collapsed in my arms.  Luckily I was able to catch her.  Her mom panicked and Sophie quickly came to and asked "what just happened."  We got her some water and she was fine for the rest of the shoot.  This is why I always encourage each senior to drink plenty of fluids before and during there session. :).   Funny thing is she had cheered her whole high school career in the heat and exhaustion and never once passed out.  That was the first time that had ever happened to her.