Grand jeep cherokee shuts off in hot weather

Hi All,

Last summer my wife’s 2000 Grand Jeep Cherokee began shutting down while driving (electric stays on) on early hot days after about 40min of driving; even when the AC is off. About 10min laters we can restart as before (before that it won’t even crank). Over the winter the problem went away but returned again this spring/summer with the hotter weather (>80C). Its not the no battery or alternator and no one can seem to figure out the problem. Any thoughts? Thanks for your help.

sorry meant 80F