Heat Headache??????????????

I went to a fair 2 days ago, and yesterday i felt kinda bad but i thought i just went on 2 many rides.

Today is better but i kinda have a headache and I was wondering if its because it is really hot and maybe I'm not drinking enough water i've never had this happen before, I mean i ate a lot of junk food there but i had like 2 bottles of water when i was there so i dont know. im 15.