It kind of sounds like heat soak - vapor lock. I.e. gas vaporizing in the lines. It shouldn't be a problem if the fuel system is pressurizing correctly though. If you got winter gas and it is still hot there that would increase the potential.
I'd go to a shop that has a gauge or get one and check the fuel pressure given there was issues with the fuel system that lead to these issues.
My engine is hard to start when it's hot. How come? — Yahoo! Autos