That is an issue a lot of us have. Helmets are a touchy subject that most wont even argue. I wear a half helmet in the hot temps and a full in cooler weather but that's me. My issue with full helmets is a pain that they cause just above my forehead that is killing me after a couple of hours must be my head shape as all healmets cause it. Full helmets need great airflow to keep cool and if you have changed the stock windscreen you limited the airflow. Sorry I don't have a better answer for keeping your cool....