Yeah, another part of the problem is that you cannot tell that you are hyperthermic and or dehydrated.

Thats how you get the people that dance all night and then just die, or go comatose or pass out.

Your body stops telling you wow, i am way too hot and wow, i really need water.

Sort of like that rare condition where you literally cannot feel pain, and children with it will break their fingers because it feels weird.