Biking and Belly Aching

I rode for 30 minutes. It was a nice ride, but hot. I really should go earlier in the day. Since I've returned, about 2 hours ago, my stomach has felt queasy. I figured it was the heat, but it's very annoying especially since I made a point to drink water throughout the day before my ride. And some during my ride. And after my ride. I'm making some rice for lunches this week, so I'll have some of that when it's done and see if it helps.