You can never be too careful. I have been using surgical masks religiously, but the number of infections in Japan has risen twelvefold in just the last week and I am starting to think that I will need to stock up on KN94 masks for any outing that involves boarding a train (which is just about every outing other than my nearest supermarket). I am starting to feel like just not going out at all is going to be my best option, but I realize that isn’t an option for everyone.
In any case, I do not want to be anywhere near any person who is not wearing a mask. I keep having this bad dream where I’m out shopping and I suddenly realize, “Oh my god, I forgot my mask!”