Summertime and Roasting in the Cockpit Heat. What's the solution?

[Trackrat]

Here we are, prime tracking season and it is getting hot.

Drawing on the voices of experience here: What is a good solution for reducing body temps?

1. Ice pack garments?
2. The cool suit solution with an ice chest?
3. The tiny but pricy electronic system? (http://www.coolshirt.net/racing-liquid-cooler.html)
4. Some sort of air ducting solution off the cars A/C system?

If using driving suit tubing, how do you correctly pass the tubes through your firesuit? Out the crotch zipper? Cut a hole in the suit??

Who has a solution that they like? Kindly share?