Okay, this may seem like an odd request.
I was at a yoga class where the temperature was 105 degrees (F) and 40-60% humidity. I tried to drink water before class as recommended, but I kept pissing it out about five minutes after I drank it. I spent most of the 90 minutes on the floor trying not to black out. It's nearly three hours later and I'm still a bit dizzy, I'm surprised I was able to drive home.
If I were to try this again, how would I retain water? What can I do now, even? I still feel kind of dizzy.