I had a similar incident this past weekend. I was scoped in on a nice doe, released my breath and my glasses fogged. I had forgotten to move my face mask and it sent the warm air straight up... DANGITALLTOHECK!!!Scope was fogged over....biggest funky buck on property....looks through scope and from being dumb and taking gun from house to truck caused scoped to fog....needless to say I didn't get the shot....lesson learned...doh