To be clear about N-95 masks and smoke, they can help reduce inhalation of some smoke particles if the mask is properly worn and fitted. (Retired ICU nurse; my hospital had staff scheduled annually for mask fittings.) The mask must be sealed to the face with two straps. If it's not sealed snugly and/or if you have facial hair (like Bob and me), you might as well be wearing any mask in terms of protection. It's my understanding that wildland firefighters don't wear face masks of any kind because they don't offer effective protection and masks make it too hard for them to breathe with the heavy exertion they perform. (Protection from COVID by masks is a little different. Virus particles are being filtered, not smoke particles and toxic gases. Numerous studies prove that masks provide effective protection, which is why doctors and nurses won't enter a COVID patient's room without one. But they must still be worn properly. And yes, there are multiple studies showing that masks are very effective in preventing viral transmission in public spaces indoors.)
