When I'm stopped or going slow I crack open the shield. I haven't found a good anti-fog that's 100% effective. When it's cold enough, my glasses sometimes fog up even with the shield cracked open.
hmmm take ur shield off?..... I remember someone or somewhere that it was stated to use "non whitening" tooth paste. (with no abrasives) ... smear it around on the shield. clean it out... it's virtually fog proof....But I could be wrong....