My body naturally gets very warm, very quickly, with very little exercise. If they can make this work, I might actually be able to wear a suit all day! Luckily I don't need to but that's beside the point.

Assuming they can get the size and look sorted so the average consumer doesn't become a social pariah by wearing one (calculator watches come to mind), I wonder how this is powered? And more importantly, would it last for 8-12 hours on a charge?