Vapor lock: Rather than letting it idle I would suggest going easy on the throttle for the last 5-10 minutes of driving. You'll have better airflow to cool things if you are moving.
And then popping the hood when you park to let the heat out. Do you have a digital temperature gauge running off...
Could be vapor lock where gasoline vaporizes in the fuel lines. Heat in the engine compartment rises rapidly after shutting down.
This gets worse with a low fuel tank. The gas recirculates through the engine compartment getting warmer with each trip.
Beach driving, driving up a mountain...