The surge of Covid-19 cases and deaths in America over the summer resulted from a toxic mix of factors: states reopening, lockdown fatigue, and a season typically filled with vacations and holidays like Memorial Day and the Fourth of July. People gathered and celebrated indoors — at bars, restaurants, and friends and family’s homes. Millions of people got sick, and tens of thousands died.

This fall, experts worry it will all happen again: States are rolling back restrictions, people are eager to get back to normal, and Thanksgiving and Christmas are coming up. America may be on the verge of repeating the same mistakes, which would risk yet another surge in the Covid-19 epidemic.

Coronavirus cases have already trended up since mid-September. On September 12, the US hit a recent low in its seven-day case average of around 35,000. As of September 26, it was back up to almost 45,000. The surge doesn’t seem to be driven by any one particular state but rather upticks across much of the country all at once.

Part of the problem is America never really suppressed its Covid-19 cases to begin with. Think of a disease epidemic like a forest fire: It’s going to be really difficult to contain the virus when there are still flames raging in parts of the forest and small embers practically everywhere. The country always risks a full blaze with each step toward reopening and with each failure to take precautions seriously.

The fall and winter threaten to make things much worse. Schools will continue to reopen. The cold in northern parts of America will push people back inside, where the virus has a much easier time spreading than the outdoors. Families and friends will come together for the holidays. A flu season could strain the health care system further.

Read the full article about surging COVID-19 cases by German Lopez at Vox.