Eh, I don't think the issue here is stupidity. Most people aren't aware of how heat affects the body and have received no formalized training about heat exhaustion. I only received such training because of some outdoorsy jobs I have done in the past, and even then, I didn't learn a heck of a lot until I bothered to inform myself because I was a supervisor. I never recall being taught anything about heat stress in my K-12 education, nor in college. Combine a lack of education on heat stress with what is probably general ignorance regarding animal physiology, and that's a recipe for people making bad decisions because they're uninformed. Hell, even when they're informed, people will not take the dangers of heat seriously.
The problem to me in this case wasn't the lack of awareness about heat stress, but use of punishment more generally. As an educator, she should be well aware that punishment is ineffectual as a teaching method compared to positive or negative reinforcement, but she did it anyway. I think the OP is being more than a little overdramatic about this particular case, but I'll forgive them for that considering the news piece itself is sensationalist drivel.