Looks like great tech, but I think I'd have to be REALLY hot before I actually wore it. I can see me using it to carry, and pull out of a bag to quickly cool down, but I think it's way too bulky to actually wear.
If you're in the desert, or in a jungle, yes, it'd be a Godsend, but otherwise, I'd have to say I'd wait for version 2 or 3, when the tech gets smaller and sleeker before it was a wearable device for me.