I bought a vest from a company called "steele"...the product is called steele vest. I drove at the july event at hallett (needless to say it was hot @ 90 degrees) the past 2 years.I can safely say there was a big difference with and without the vest. The only problem is keeping the packets frozen not just cold ! An option I have found is there are 12v powered freezers(expensive) : ( I am currently exploring a 12v powered a/c unit that hopefully when done will weight less than 25 lbs. about the size of a large shoe box and draw less than 30 amps...cost @ 2,000 $ I know that's a lot but, the current units used in nascar cost about 10,000$ Wish me luck ! mdg.