has anyone seen these vest http://www.allegrosafety.com/catagories/cooling_products/index.html

I've got some similar items. They are basically a linen tube filled with water absorbing gel beads. You soak them in cold water for at least a couple hours till they are fully hydrated. Once hydrated, they can be loosely tied around the neck and do a fairly decent job of cooling via evaporative process. They will last a couple of hot summer days before needing to be reydrated. You can't wash them out with any kind of soap or detergent, or the gel becomes contaminated and deactivates.

They are a very cheap way to stay cool on a hot summer day. They are based on the same principle of dipping a bandana in water and tieing around the neck like Grandad used to do out on the range.