Dennis, I used the Fieldshear brand
Iceberg POLYMER vest, and it was damn heavy, heated up and lost all water in no time. So I gave it away.
Later, I discovered a different type of vest, mostly sold to be used by road workers and such, that uses a crystal water retaining technology, and these vests, once fully charged with water (can take a few hours or overnight), will stay wet for days (not hours).
They
all are still supposed to work best
over a tshirt, and
under a lightweight full (not partial) mesh jacket, and not just exposed to the wind stream.
This is what I am talking about. (*there may be others out there, just google
water retaining crystal vests) (scroll down for other crystal cooling products)
http://www.tuffsupplies.com/occunomix-902-miracool-pullover-cooling-vest-37174.htmlhttps://www.fullsource.com/occunomix-902-073/?gclid=EAIaIQobChMIzKS8l6Ou2wIV1lqGCh1StQyREAQYAyABEgIlvPD_BwEhttps://www.thewarmingstore.com/miracool-cooling-vest-900.htmlhttps://www.amazon.com/s/?ie=UTF8&keywords=miracool+cooling+bandanas&tag=googhydr-20&index=aps&hvadid=228972139383&hvpos=1t2&hvnetw=g&hvrand=17091445895816617683&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9008188&hvtargid=kwd-377913625196&ref=pd_sl_8vo8czmbkm_e_p38What I did was charge the vest overnight in a big container of water, then I folded it up in a big oversized zip lock plastic bag and stick it in my fridge. On a hot day ride, I put it in my saddlebag (still in the zip lock bag) (it would be too cold to wear right out of the fridge... shivver). But later, as the day heated up, I'd pull it out and stick it over a tshirt (recommended), and under my all mesh jacket. It will hold water for days, though once your body heats it fully up to 98.6 degrees, it gets feeling pretty muggy, even with the evaporation working. My vest also was a bit long for my body (while sitting on the bike seat), so I cut the bottom front row of crystals off it, because I was getting wet nuts/ass which was not helping with the cooling process.
The polymer cooling vests suck.
The brand name for this crystal stuff is MiraCool, and they also make some crystal holding doo rags, and neckerchiefs which also help out with hot weather. I especially liked the doorag, which only had a row of crystals for water right in front. My half helmet was too tight to go over the water crystal row, but I was able to shift it forward to just below the front crown of the helmet. Adding evaporation to forehead and neck was a big help (often without the vest), and this stuff is pretty cheap, and ordered 4-5 different items for try out. (I left some charged with water in the fridge all summer long one year, and the cotton fabric sort of prematurely wore out, so don't do that)
