So worrying is the new wave of Covid-19 infections that it seems unwise, even reckless, for anyone not to wear a face mask in public. But as the situation is seemingly getting out of control – with three days of three-digit increases in a row, there are those who still do not take the expanded mandatory mask-wearing order seriously. Not only are they at risk of being infected, public health is also jeopardised as a result of their irresponsible behaviour. Authorities must step up enforcement to avoid it becoming a mere token measure in an escalating battle against the deadly coronavirus. Citizens should also heed the government’s appeal to stay home to help curb transmission. Most Hongkongers, to their credit, were wearing masks months ago when the world was still debating the use of face coverings. Today, few would question their effectiveness in reducing transmission. We are therefore justifiably proud to have set a good example in curbing the disease during the early stage of the epidemic. Unfortunately, fatigue and complacency set in following the second wave of the outbreak in March. Then, a relaxation of social-distancing rules by the government also led to the wearing of masks and other protective measures becoming not so widespread. The resurgence of restaurant clusters and related family infections this month underlines how vulnerable the situation we are in really is. The growing number of cases linked to a banquet at a Mong Kok restaurant celebrating the 23rd anniversary of the city’s return to Chinese sovereignty illustrates how the contagion spreads easily among gatherings, even when people just briefly take off their masks in crowded areas. Tighter measures as Hong Kong hits daily record of 113 Covid-19 cases Separately, the recent wave of infections of unidentifiable origin – now running into hundreds across different districts – means there could be many hidden transmission chains in society. That makes the mandatory wearing of masks, now extended from public transport to public indoor places, such as shopping malls and supermarkets, all the more important. According to media reports, some individuals remain defiant but, as of Wednesday, only 22 verbal warnings and one ticket had been issued in relation to not wearing masks on public transport. More forceful enforcement is needed. The need for people to stay united in fighting the virus has never been higher. Until a vaccine becomes widely available, masks remain an essential part of our armoury. With free government masks now available and supplies on the private market relatively adequate, there is no excuse not to put them on. If the hot weather makes wearing a mask uncomfortable, the alternative is to stay home as much as possible. Unless everyone strictly observes the rules and follows official advice, there could be dire consequences for public health.