Will a windproof balaclava make my goggles fog more?

It can, if you choose a model without breath management features. Windproof membranes reduce breathability, which means breath moisture has a harder time escaping and is more likely to fog your goggles. However, the best windproof balaclavas address this with mesh breath zones, directed exhaust channels, or hybrid construction that maintains breathability at the nose and mouth while blocking wind elsewhere. If fogging is a concern, specifically look for models with these features—they can actually fog less than non-windproof balaclavas that lack breath management design.