A study on Covid-19 transmission suggests keeping a 2-metre distance indoors without a mask is not enough to prevent it from spreading.
Experts at the University of Cambridge and Imperial College London found it's more likely to be caught inside by two people talking, rather than someone coughing.
Their study says it's because water droplets released when people speak are so small they linger in the air.
Meanwhile, Germany has introduced a new rule that will ban people from using makeshift face coverings such as handmade cloth masks or scarves.
Instead the public there will have to use to use full protective filter masks in shops and on public transport.
It comes as the national lockdown in Germany has been extended until February 14th.