1999Ford Taurus won't start again after running using A/C. Will eventually re-start when engine cools.

1. On a warm day with A/C running, upon slowing to a stop, engine falters, dies, and will not restart.  Will crank over, but sputters like it is not getting gas.
2.  On a warm day with A/C running, I stop to do a quick errand.  Car not not re-start, acts like it is out of gas.
3.  In both examples above, the car will re-start half hour or so later and drive fine.
4.  This is an intermittant issue and has happened 6 times, twice blocking traffice upon failure.