replacing my fuel pressure regulator and fuel filter got rid of the problem for me.. exactly how you described it but for me it was a weekly problem. the odd thing though is that mine seemed worse in the winter time
I doubt heat is the issue. I live in BHC which is in the middle of the Mohave Desert (for those who may not have heard of it) are summers are always in the 110 degrees plus. Last summer we had a dozen days in a row where the temp was in the 120 degree plus area and over 100 at night. Never had this issue. That being said whatever the issue is may of course be complicated by heat.