After insisting masks were unnecessary, US health authorities are now telling people to cover their faces in public to protect themselves from spreading or catching coronavirus. But in Australia, the message is that masks are crucial for health workers, but not recommended for the public. Dr Norman Swan and health reporter Tegan Taylor discuss the merits of masks, and if wrapping a scarf around your face will help. On today's show: * Masks. What's the deal? Do they work? * Why am I having such wild dreams at the moment? * If you need an urgent repair in your home, is it safe to ask a tradie to come over? Norman and Tegan also discuss a new study about how blood pressure medication and if it increases the risk of problems if you get COVID-19.