Here is an inexpensive cooling vest for those of us doing armor builds.http://www.bonanza.com/listings/Ice-Vest-2...ic-Set/16947068
This one too,,,little more money, but more cooling.http://www.amazon.com/Flexi-Freeze-Ice-Ves..._sim_sbs_auto_3
Good find Finn! Those will definitely come in handy.
I would go with the Flexi Freeze, The other one would just be too easy to make. Wish I could still get ahold of the gel stuff we played with in school, don't remember the name of it but it was gel granules, that you could even stick in the fridge. Simple sew them into a vinyl pouch and seal it then stick them into a vest. Those things stayed cold for days.
I am planning to use a kind of brown soap (semi-liquid, gel-like and so on) in plastic bags. That stuff will stay cold forever and will take the shape of whatever they're put on. We used them at my old sports school to treat injuries.
The only downside is, it's kinda heavy.