For the past week, Hong Kong retail store owner Dora Ho has been wearing a medical mask wherever she goes. She doesn’t let her husband leave the house without one, either. The couple have a dozen boxes of them at home, and started their stockpile as news reports began to pour in about a deadly, pneumonia-like coronavirus that first emerged in the central Chinese city of Wuhan. As well as the standard 3-ply and 4-ply masks, Ho has a box of 3M-made N95s, which have been increasingly expensive and difficult to find in Hong Kong since the Wuhan outbreak started grabbing headlines.