I don't do well in this heat!

I like this weather when it's not to hot. When it gets to hot i don't do so well. Last year I had 5 heat exhaustion. I end up in the hospital last year twice. Right now I feel like crap. Am I not drinking enough water. Am I not eating not enough fruit. What am I doing wrong? I got a mass headache and a fever. I hope I don't end up in the hospital at all this year. I

I still haven't seen him. I was going to call him today but I don't feel well.