What if you didn't have to worry about your smartwatch's battery? The PowerWatch may be the answer to that problem.
http://www.notebookcheck.net/Crowdfunded-smartwatch-is-powered-by-body-heat.183991.0.html
I have cold fingers, so by extension probably cooler than normal wrists ... maybe it's lower than average circulation, I dunno. Probably enough to have an impact on this item, though.
You see this cat Duervo is a cold mother
(shut your mouth)
But I'm talkin' 'bout Duervo
(Then we can dig it)