Are you still using a cloth or surgical mask in indoor public spaces like grocery stores? Are you or someone in your household >40 or otherwise at high risk of severe COVID? If so, it’s time to upgrade your mask. A : 1/9

I personally wear a 3M 8511 valved N95 mask any time I enter a building. For lower-risk settings I reuse them, and use a new one anywhere there might be someone unmasked. They fit well and make it easy to breathe clean filtered air for hours if needed. 2/9

My valved N95s protect me from others’ aerosols, but don’t protect others as much if I become infectious. When I also need to protect others, such as for getting my MMR or flu shot, I put a surgical mask over the N95’s valve. 3/9

When outdoors (exercising, etc.), I generally rely on keeping 10ft+ from others (going out of my way into grass or bike lanes as needed) and only wear a mask if there’s wildfire smoke, but I also carry a flat KN95 in my back pocket in case I need to go inside. 4/9

Many people are still wearing cloth masks, either because non-valved (K)N95 masks are a bit harder to breathe through, or because they think there’s still a PPE shortage. In fact, N95s and especially KN95s are widely available online for anyone to buy, so you should do so. 5/9

I’ve now bought two packages of 3M 8511 valved N95s from http://cov.care , which has them for about $8 each. They also sell non-valved N95s suitable for healthcare, but I recommend valved N95s or KN95s for civilians, to save the healthcare-rated N95s for HCWs. 6/9

If you would rather buy through a better-known site like Amazon, you can easily acquire KN95s there. I would buy several different brands, and try them all to see what fits most snugly against your face. You may need to tie a knot in some ear loops to get a non-leaky fit. 7/9

A well-fitted KN95 or N95 should not allow any air around the mask when you sharply inhale or exhale: they shouldn’t fog your glasses/goggles. If they do, adjust the nosepiece or tighten the straps to avoid any SARS-CoV-2 droplets or aerosols getting around your PPE. 8/9

Until we get through this pandemic, all of us who value our families lives should be doing what we can to protect them. That includes wearing a mask good enough to protect yourself, and by extension all of them. I bet you do care, so get yourself a N95 or KN95 and wear it. 9/9