After being extremely careful all summer, I went to a friend’s house for a cookout in late September. I came in the front door and, on the way out to her backyard, stopped in the kitchen to talk for a while. It was getting chilly out and the fire pit wasn’t going yet, so we chatted and dawdled and chopped some stuff up, and chatted some more.

Before I knew it, we had been inside for more than 45 minutes, without our masks on, talking away, puttering around in a small kitchen, less than six feet from one another.

We are both fine, but that’s because we were lucky rather than smart.

What we were doing is exactly the kind of behavior that could be contributing to the recent uptick in test positivity rates in Connecticut, experts say. Contact tracing has shown that the spread of virus is occurring in households and during small gatherings and social occasions.

“People come inside to eat or drink or socialize, believing their friend from down the street, or from out of town, certainly could not have COVID because they look fine,” said Dr. Deborah Brix, the coordinator of the White House Task Force, in early October during a visit to Connecticut to meet with state officials and health leaders. “Really, if you’re gathering together indoors, assume that someone in that group, outside of your household, could be positive. Stay physically distanced and wear your mask.”

If you do go to a gathering and decide to take off your mask, get tested.

“Maybe I went to a party and took my mask off. By party, I mean it could be six people at someone’s house. Five to seven days later I should go get tested, because I can’t tell if someone’s sick or not,” Brix said.

She says as it gets colder, the northeast runs the same kind of risk that the south faced as it got hotter this summer.

“It got hot, and people moved indoors” into the air conditioning, she said of the south, where infection rates skyrocketed.

Likewise, here, as it starts to get colder, “people start to move indoors” to stay warm.

If you are going to visit someone who is not in your immediate household, stay physically distant and wear a mask, Brix says.

Both Governor Ned Lamont and Department of Social Services Commissioner Deidre Gifford, who also is the acting commissioner of the Department of Public Health, repeated that message later that day.

Gifford said continued vigilance is needed to protect co-workers, friends, and family as we continue to reopen the economy.

But when people attend smaller gatherings with people they like, they like to assume that, since we know them well, that they are fine. It’s normal and reassuring to treat others—and be treated—like we are all fine. But that is dangerous during these abnormal times. There is really no way of knowing.

For anyone who does get sick, it’s so important for those people to participate in contact tracing, so that others can be notified to get tested. And for those who have been exposed, it’s important to stay home and away from others for a full 14 days at least. The ability to keep those we care about safe and the economy in Phase 3 in Connecticut is in the hands of its citizens, officials said.

“Where there are outbreaks, we have to break the chain of transmission,” Lamont said.