Down here in South Carolina, we know all about skeeters and heat. These are a necessity for me:
Don't use a climber if at all possible; you'll be soaked by the time you make it half way up the tree.
Bug tamer with a tank top and shorts underneath.
Thermacell for those nasty blood suckers.
Camelpack full of ice water.
Scent wafers and cover scent spray. I use lots of cover scent because your gonna sweat.
Most importantly, hunt with the wind inyour favor.