More than 4,400 Pennsylvania coronavirus patients were in hospitals on Monday morning, a record increase that the state’s top health official called “a concerning milestone,” while New Jersey sharply cut the number of people allowed to gather outdoors and nixed high school ice hockey until January.

While too early to know how much the virus had spread at Thanksgiving celebrations, officials advised anyone who traveled to quarantine and were already asking people to begin preparing to stay home for Christmas, Hanukkah, and other winter celebrations.

“This right now — this November, December, January, February — looks like it’s going to be the peak time in terms of transmission of COVID-19,” Pennsylvania Health Secretary Rachel Levine said. Once vaccines are distributed, she added, “I think 2021, especially the second half of 2021, will look much better.”

In order to get through until then, she said, people need to follow public health guidelines as closely as ever — especially as hospitalizations and deaths rise. Since November began, the average daily number of people hospitalized has more than tripled in Pennsylvania and more than doubled in New Jersey, state data indicate. More than 500 Pennsylvanians have died of virus-related complications in the past week; that number is just above 200 for New Jersey.

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Public health officials across the country continued to grapple with rising case numbers, and brace for a potential post-Thanksgiving surge in infections.

New York Gov. Andrew Cuomo set a new batch of emergency measures aimed at avoiding hospital bed and staff shortages, saying his state would not “live through the nightmare of overwhelmed hospitals again.” A bevy of new restrictions went into effect in Los Angeles County, including those reducing the number of people allowed in grocery stores and prohibiting most gatherings.

And while some were still digesting the last of the leftover turkey, officials on Monday began asking the public to prepare to stay home for December holidays — calls that were being echoed across the world.

European countries were grappling with what to do about traditional Christmas markets and ski resorts; Turkey announced weekday curfews and weekend lockdowns; and Spanish officials implored people to stay home after massive shopping crowds came out over the weekend. The World Health Organization’s director warned that holding festivities for the upcoming holiday season could be “gambling with” people’s lives.

“This year, we need to change how we enjoy the holidays,” New Jersey Department of Health medical director Ed Lifshitz said Monday.

Get tested if you had Thanksgiving with others, officials say

New Jersey Gov. Phil Murphy encouraged anyone who spent Thanksgiving with nonhousehold members to get tested. People who were at gatherings last week may want to “assume they were exposed and to quarantine,” Levine said.

Because it takes some time for people who contract the virus to show symptoms or test positive, it will be several days before public health officials have an idea of how much the virus may have spread at Thanksgiving gatherings.

But it is almost certain there will be an effect on virus case numbers, said Donald Yealy, chief of emergency medicine and senior medical director for the University of Pittsburgh Medical Center.

“I think it’s very likely this will not be an ‘unevent,’ for lack of a better term,” he said.

Anyone who experiences symptoms should get tested, and people without symptoms who want to get tested should do so about a week after they could have been exposed, officials said.

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Philadelphia International Airport and 30th Street Station spokespeople did not yet have a tally Monday of how many travelers passed through over the last week, though federal data showed the millions who flew nationwide numbered many fewer than last year.

Murphy said anecdotal evidence suggested most residents heeded public health warnings and kept celebrations small. Some numbers from the New Jersey Turnpike, however, indicated a significant number of people hit the highways, though fewer than in 2019. From Tuesday through Sunday, there were 7.9 million tolls taken on the Turnpike and Garden State Parkway, compared with 10.1 million last year, according to the Turnpike Authority.

Levine said Pennsylvania’s recommendation for winter holidays is to stay home. New Jersey officials in the coming weeks will issue safety guidelines for everything from family dinners to Christmas tree-lighting events.

Caroling and singing groups should keep away from each other and wear masks, Lifshitz said. Holiday parades and in-person visits with Santa are discouraged. If done, children should not sit on Santa’s lap, and reservations, masks, and social distancing should be used.

N.J. aims to stem outbreaks among youth hockey players

In another bid to suppress the ongoing surge of new cases as winter approaches, New Jersey’s limit on outdoor gatherings will be reduced from 150 people to 25 starting Dec. 7. There are exceptions for weddings, funerals, and certain other activities.

Murphy said the state was better positioned to handle outbreaks than in the spring and dismissed speculation a broader shutdown was imminent.

“Today we see more moves on the board that we can take,” he said. “We have much better data and science to draw from. … And we can focus restrictions on the activities that have been proven to have the greatest risk of transmission.”

The only interscholastic sports season affected by the new restrictions is ice hockey, the New Jersey Interscholastic Athletic Association said.

Other indoor, high school sports had already moved the start dates of their seasons to January or later, the NJIAA said. “We’re hopeful that, with schedule modifications, the ice hockey season will be viable when the state’s pause is lifted,” the organization said in a statement.

Indoor hockey alone has led to more than 100 cases, Lifshitz said.

The regulations, effective Saturday, will be temporary and do not affect college or professional sports. Outdoor youth and high school sports will still be allowed, but games and practices will be capped at 25 spectators.

“I hope and intend to see the winter sports season in January,” said Murphy, noting that his four children all play sports. “I want to see especially that high school senior get to play her or his last season. … But we are seeing outbreaks related to indoor sports, and this is a prudent short-term step to slow the spread.”

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Hospitalizations being watched

Though Pennsylvania has far surpassed the number of people hospitalized at any one time during the spring surge, none of the commonwealth’s health-care regions have reached the metrics set by the state last week that would require hospitals to cut down elective procedures to free up space.

Still, Levine said, some areas are strained and state officials are “very concerned about the hospital capacity.”

Of the 4,405 people hospitalized, 970 were being treated in intensive care units as of midday, according to state data, and nearly 500 were on ventilators. Across the commonwealth, 796 adult ICU beds remained available, according to that data.

In Philadelphia, 788 patients with COVID-19 were hospitalized as of Monday, the city reported, up 48% since Nov. 18, when 530 coronavirus patients were in the hospital. The city also reported 1,784 new cases since Friday, lower than recent weekends, likely due to Thanksgiving lab closures.

More than 500 Pennsylvanians died of virus-related complications in the past week. Levine said officials are seeing more deaths outside of care facilities than they did during the initial spring.

“This winter is the key time,” Levine said. “We all need to stand united; we need to stay home and prevent the spread of this virus.”

Staff writer Rob Tornoe contributed to this article.