|The chilling effect of dry ice on beer|
The answer to this question is simple: dry ice.
In San Diego, there is a store called 'Smart and Final' near the Sports Arena. They have a dry ice container. You can buy a thin slab for 15 bucks. Throw that in the bottom of your cooler or ice chest with a bag of party ice (or better, block ice), and you can expect extremely cold beers for many days.