If fitted properly the fogging should not be an issue. That can be difficult to maintain on some people's faces though. Using a headband style instead of ear loops can make a big difference for a tight fit. Some medical users will use a little bit of bandage tape to seal up the top, which may be a little difficult to keep up with for average users, but may also help remind people that masks don't work very well when you're constantly taking them on and off. If you're in a place with potential clouds of aerosols floating around, the mask should stay on the whole time.