It would need batteries, it would probably need a lot of power so they would be heavy batteries, also you need to do something about the heat. A/C doesn't really cool rooms so much as it pulls heat out of the room and pushes it outside, the heat has to go somewhere so you'd need a fan or something poking outside of your clothes for the heat to be dumped.

[–] WrongOnTheInternet@hexbear.net 4 points 2 months ago

Small fans that clip to your clothes or hang around your neck have existed for a while

They're reasonably effective even in higher humidity because the body heats the air immediately around it a bit higher than the rest of the environment