I'm thinking that the IAC is dirty/faulty which is exaserbated by heat. Try cleaning as I said, whil ethe car is runnig so it sucks the stuff through.
2000 SVT Turbo 295hp/269ftlb@12psi
#1 for Bendix Brakes Kits!
Knuckles rebuilt w/new bearings $55
AUSSIE ENDLINKS $70
Gutted pre-cats $80/set
A lack of planning on your part does not constitute an emergency on mine!