If you are frequently monitoring the data, maybe consider your cadence. I asked Salemi if people who are very worried about COVID should really be checking four or five pandemic metrics daily. “I think you’re doing yourself a big disservice if you’re looking at these numbers every single day, because there are reporting anomalies and things that change,” he said.

Tara Kirk Sell, of the Johns Hopkins Center for Health Security, said that she’s personally watching COVID case numbers “mostly to understand trends” and assumes they’re undercounted. “I don’t worry too much that I don’t know exactly what the level is since ‘a lot more people are getting sick right now’ is close enough for personal decision making,” she told me over email.

Elizabeth Carlton, an associate professor at the Colorado School of Public Health, suggests starting with the CDC’s community-levels map, which assigns counties colors using a combination of three metrics (one of which is cases). Green is low, yellow is medium, and red is high. If your county is in the red, then “no more data-sleuthing needed,”she wrote in an email—start wearing a mask indoors. If it’s yellow, “a simple approach is to round up.” As for green: “Personally, I have been treating green as low-risk and, in that case, rarely wear masks in public unless it’s really crowded. That said, I don’t have an immune-compromised household member and at least one person in my household already had a SARS-CoV-2 infection.”