Been doing some research for some type or kind of shirt to wear under our uniforms to keep us cool in the hot summer months. I've come across several air wicking or compression shirts that uses your body sweat to keep you cool and dry. Others have small water lines in the shirt but require a pump so that's out of the question. A company called Leatt on my route makes this vest that you can soak in ice water or the freezer and it says it will keep you 10° to 20° cooler. (It's $80 by the way) So they were nice enough to give me one to try out. They also have one with ice packs you freeze and works even better. ( that one is $350) Well after about two hours I was dying and had to take it off and put it in my ice cooler. It did keep me cooler. It's a little snug but you get used to it. Really felt good to put it back on towards the end of the day for one final relief from the heat. The jury is still out on this vest but there is technology out there. Anyone else find something like this?