AFAIK masks outside in big cities is because people otherwise tend to forget to put them on when going inside (say in a shop). Add this to surgical masks being

AFAIK masks outside in big cities is because people otherwise tend to forget to put them on when going inside (say in a shop). Add this to surgical masks being designed to protect others rather than the wearer, (it was really noticeable to me when after switching from a surgical to a FFP2 mask my ~hay fever symptoms disappeared), and you can see how it makes sense to switch that mandate on when it looks like hospitals are going to overflow soon.