One item I really like is this buff headwear. It’s really overpriced in my opinion (15 EUR for a piece of cloth that probably costs about 0.15 EUR in production). Anyway, I got one. I always have it in my backpack or wear it around my neck when it’s cold. When I’m in a place where I don’t feel good about the air, like a moldy basement or very dusty ruins, I turn it inside out half way so I get a shorter version of it with two layers of cloth, and just pull it up over my nose. It’s probably not an adequate respiratory protection and won’t protect from more hazardous stuff like asbestos, but it’s tiny and I always have it with me in my backpack. It can also be quite fashionable, if you like to look like a terrorist every once in a while.

Check Buff Headwear prices on Amazon. Look for cheap Buff Headwear on eBay.