Unfortunatelly, not everything what can be attached to hand we can call a watch.
If we compare with Apple watch, which can be called a watch since it is probably not bigger than 1inch2.
It will be difficult fit this prototype IR camera inside 1inch2, than ok it could be a watch, but for the moment it isn't...
My watch with sun tracking software will be for sure ~1inch2, because of I wouldn't like to tell someone it is a watch, unless it has a size which is practical for everyday use.
BTW: Fireman will be more happy with IR camera in his helmet, because of he wants have his hands free and ready for action and his hands have to be rather protected from heat not exposed to IR