When it’s wise to wear a double mask

Double-masking is largely about fit. … A surgical mask alone, for example, often has big gaps at the edges, allowing for particles to easily enter and leave. “It leaks like a sieve, it leaks like crazy,” said Jim Smith, a chemist and expert in aerosols (small particles) at the University of California, Irvine. “Surgical masks need a way to seal better around your face. That’s the whole point of double masking, in my view.”