Had the beginning of heat stroke back in my mid-20's whilst attending a motorcycle event. Quite hot and humid, I had no hat, and failed to hydrate properly. All the beverages that were available were soda pop and beer, and somehow the cola I had didn't make it any better. And no, I didn't want beer since I'd had a bit too much of that the night before at the campground - which probably also contributed to the dehydration!
There was no plain water available anywhere on the track, so finally found a stand selling cartons of milk. Had a few of those and it put me right, plus I stayed in the shade.
Hope you're feeling more chipper now Ozzie.