1995 Explorer 4.0 Overheating Problem (yes, I've searched already.)

[iatefish14]

My girlfriend has a 95 Explorer 4.0 that is overheating. She told me that one time, she was driving around and went to go get gas. Her car was overheating before she shut it off. After she gassed-up, she went to start her car and it would not start. She waited a few minutes, tried to start it again, then succeeded. She also has told me that this has happened on a few other occasions. I replaced the thermostat and did a coolant flush on it. The water pump looks new and the radiator is not leaking. The coolant levels are fine- radiator is full and reservoir is to the fill line.

I've done searching throughout this forum- "cats clogged", "thermostat needs replacing". However, I haven't found any symptoms such as what my girlfriend has described to me.

Any input would be a great help. Thanks.