Should I keep my doors and windows opened or closed to remain cool in my house?

I'm in Florida and I have no AC. I refuse to pay $100+/mo for AC when I could invest that money. Anyway, I was told by some people you shouldn't try to cool the outdoors. Other people are telling me to leave my doors and windows open to get a breeze in the house. I use a small fan to stay cool. Who's right? Should I open or close my doors and windows?