I hunt in central Texas where summers are really humid. Yesterday it rained on and off for a few hours before sunset. Before my hunt last night I put my thermal on the charger like I always do. It’s in my barn office which is nice and cool. Too cool… When I got up into the stand I realized the whole gun was sweating like an Icee. Both ends of the optic were completely fogged over. I almost called it because it was so humid. I decided to wait it out, after about 30 minutes it dried out and became usable. Another check list item for the guys in the swamps. Put the gun outside for an hour or so before you head out.