Perhaps I'm missing your point, but if you're saying the kid died from "inadequate or harmful treatment in the hospital," then I didn't miss your point and you are an idiot. Heat stroke is the reported cause of death, and it certainly is not beyond the realm of possibility to survive four days before dying of heat stroke. I'm assuming he was in some sort of coma the whole time and never regained consciousness after the episode.
But with a given cause of death of heat stroke, or exertional heat stroke, you should just leave it at that and not try to imply the medical care was anything less than it should have been.
Heat is nothing to take lightly. I've had my own episode of heat exhaustion and was lucky that's all it was. I feel sorry for this kid and have nothing but the most sincere condolences for his family and friends.