ok, some guys use fans a rave about them, if you want to carry the extra then go ahead. if you only have a standard mask then anti fog stuff like divers use is ok but it will fog up in the rain and when your hot,but just slower. i recommend a thermal or antifog lense, it is a double lense, trust me i played in the rain with my work mates and i had my scott thermal lense and they had site gogs on . they couldnt see ****, so i just kept shootin. what a day.