My dad nearly died of heat stroke when I was a baby. My boy has Asperger's. He wasn't out there very long, maybe half an hour, 45 minutes, and he had come in once to refill his water bottle. Even the old guy he was working with didn't realize he was going down with heat exhaustion. We lucked out. Now that I know he's subject to it, I'll definitely keep a closer eye on him.I took care of a roofer once in the hospital. He was so messed up from being out in the heat and sun! All his muscles kept contracting, very painful.