Mayor Marty Walsh warned Boston residents Thursday the city is at a critical point that could determine how the year-end holidays proceed — with strict lockdown measures in place or looking towards reopening.

The update came a day after Massachusetts confirmed a record one-day increase of 4,613 COVID-19 cases. The city confirmed 542 new cases, a third consecutive day of increases, according to the Boston Health Commission.

Responding to a question about potential additional COVID precautions, Walsh said the city is at a tipping point.

“It’s incumbent upon all of us. The next step is shutting everything down,” Walsh said during press conference. “We’re three weeks away from Christmas, our retailers need people to go in and shop, our restaurants need people to eat in, people working, they need to make money — that’s the last resort is wanting to shut things down.

Earlier in the week, the mayor explained the city was bracing for a spike in cases driven by the multitudes who traveled and spent Thanksgiving with extended family despite repeated warnings from government and health officials.

On Thursday, Walsh said the city is starting to see the result of that disregard and implored residents again to take the necessary steps to stop spread of the virus — wearing face coverings, washing hands frequently and using hand sanitizer, cleaning and disinfecting surrounding areas and avoiding large gatherings.

“If you’re at work and you get the virus … I can understand that,” Walsh explained. “But if you have a house party with 20 people in it, and you pass the virus around, I don’t understand that.”

The mayor also noted that the state is preparing to receive and distribute vaccines through the Department of Public Health and then through municipal health departments.

Marty Martinez, Health and Human Services chief, said the details are being worked out, but identified public confidence in the vaccines’ safety and effectiveness as the main barrier to distribution.

Walsh also pointed to the upcoming Christmas holiday and asked the public to support the U.S. Marine Corps’ Marine Toys for Tots toy drive.

“Usually, I’d be joining them at a warehouse in South Boston for a big kickoff. This year, there are challenges,” Walsh said, noting that many offices and toy collection sites are closed or sparsely populated.