Tire Pressures
That's true about running higher pressures to keep temps lower. When running the Supra Ecstas we actually found 36 psi on both ends to give the highest traction and lowest temperatures. This was found using a skidpad, g-meter, and pyrometer.
However, if the tread is not shaved down to at least 5/32 or 6/32 maximum depth the tires will overheat at ANY pressure. I know for two reasons. Firstly, my pyrometer tells me so. Secondly, after four track days, my Supra Ecstas are always toast when they haven't been shaved.
Running street tires at full tread depth results in two problems. The tires go through extreme heat cycles which causes the rubber compound to harden, increasing lap times after every day's heat cycles. Even though the tires look "new", they are destroyed. Then, after more use, the heat causes the tires to chunk, resulting in tread delamination... dangerous.
If you want to run street tires, have them shaved to at least 6/32 maximum depth. The vehicle will be more responsive because there is much less tread squirm. And, the tires will actually last twice as long.