I'm confused by your question... because, again, my coach would NEVER do that to me/us.
Verbatim at the time.... before practice, "if you feel dizzy or not right, SIT OUT and tell a coach"... I played for (and now coach under) a HOFer. We also DIDN'T have a trainer.
What you're describing is negligence as a coach and disgusting behavior. We were educated on what could happen to us in the heat, though.