i got frens who apply the insect repellent on their face and
neck b4 putting camo so tt the camo is easy to remove.
i try putting insect repellent on face and neck b4 too but yes, its
SOOO hot! even on cool nite can make one sweat like hell!
den eventually started putting the insect repellent on no. 4, where
all the openings are (around the neck, around the buttons) and on
my hands, on my back and bottom. it worked quite well! 
oni time was during lancer jcc. the mosquitoes were so atrocious!
had to use camo scarf to cover face and neck else canot sleep.