Mosquitos :(

What's the source of your problem?   Do you live in a bairro with a lot of mosquitoes?  If so, and you don't have screens,  you're fighting a losing battle.
Make sure there's no standing water (e.g., in saucers under houseplants) anywhere in your apartment.   You can't do much about your neighbors, though.
From my years in the Northeast, I'm a great believer in mosquito netting.  I would close the bedroom up about two hours before bedtime, spray it with an aerosol insecticide, then air it out shortly before bed, and scoot under the net.
Mosquitoes are rather weak fliers, so sleeping with a fan on can help keep them off you.  Air conditioning is less effective,  but the cold seems to slow them down.  Good luck!