Here a small and cheap trick if you don't have (or don'T want to use) a AC unit : Cooling by evaporation..
Get a small spraying bottle with water and a fan, spray yourself with water and hang around the fan..
It's quite effective ! I'm using this trick right now while sitting in front of my computer and i's currently 29C (84F) over here (quebec province) ..
Try it,you could be surprised how effective it is..in fact,if you're doing it too much,you might start quivering pretty fast really if you're spraying around your neck

..
Schneider