This is a view from the other side of the needle. Many years ago, I worked for DY drawing blood from HS girls. In one school, the principal was very on top of it making sure there weren’t too many girls in the room at one time. If any girls started getting hysterical, he calmed things down right away. It was a pleasure. The other tech and I got things done quickly and efficiently. In an different school, they stuck us in a room about the size of a closet. There were no teachers or authority figures around. The girls started getting hysterical and before long they were dropping like flies. Rabbi Ecstien, the head of DY tried to keep order but couldn’t do it.
In general, it isn’t a big deal. IF the patient cooperates and doesn’t squirm, it usually doesn’t take long and isn’t painful. When a few vials are taken, it looks like a lot, but it really isn’t more than 2 tablespoons.