Christina Animashaun/Vox

How to make indoor air safer (but not necessarily safe) during the pandemic.

SARS-CoV-2, the virus that causes Covid-19, can float in the air. In particular, it can linger in poorly ventilated indoor spaces, spreading farther than 6 feet from its source. These indoor public spaces are high risk and should be avoided while the virus is still spreading.

But, increasingly, people are returning to those spaces: Some schools and universities are opening up, restaurants are operating in limited capacity, and, come November, (indoor) polls will open for people to vote in the presidential election. Right now, in August, it’s possible to enjoy many activities outside, where the risk of Covid-19 transmission is lower. But cold weather will push many of these activities back indoors.

To make indoor communal spaces safer, experts keep stressing, they need to be “well-ventilated.”