The coronavirus surge has put tens of thousands of Americans — including nearly 3,900 Pennsylvanians — in hospitals two days before Thanksgiving, yet nearly two million travelers flew on Sunday and Monday and officials fear people will gather with family despite warnings that doing so will increase an already unprecedented number of infections.

Hospitalizations and deaths of coronavirus patients were rising, Philadelphia Health Commissioner Thomas Farley said Tuesday. He cited spikes in infections after Halloween, when some ignored public health leaders’ requests not to get together.

“We’ve given people plenty of warnings that they should have Thanksgiving meals with their household members only,” Farley said. “You don’t want to spread COVID to your elderly grandmother or to that cousin of yours who might have a medical condition.”

Whether traveling or not, the safest way to celebrate Thanksgiving is to dine only with the people you live with and to do video calls with people you don’t, officials have said.

With the state under a stay-at-home advisory the day after the commonwealth tightened restrictions Tuesday, Pennsylvania reported 6,669 newly confirmed cases and 81 deaths.

Statewide, 3,897 were hospitalized with the coronavirus. Two months ago, fewer than 500 patients were hospitalized.

The number of virus patients in Philadelphia hospitals increased from 542 on Thursday to 672 on Tuesday. While that caseload is still well below local hospitals’ capacity to treat residents with the disease, Farley said the trend line is alarming.

More than one in 10 Philadelphians whose test results were reported Tuesday were positive. The city reported 1,077 newly confirmed cases and seven deaths.

Seventeen city residents have been confirmed to have died of the virus last week, and 31 the previous week. In August and September, the city saw only about 10 deaths confirmed per week.

“We are still seeing very high case counts,” Farley said at a virtual news conference. “And we are seeing increases in the severe consequences of this infection.”