A day after Massachusetts' COVID-19 infection rate pushed the entire state into the "red zone" of high risk, the number of infections and deaths continued to climb.

And some public health experts say the state needs immediately reverse course in its re-opening, in order to prevent another surge.

The state reported 568 new confirmed cases Thursday, up 50 from the day before. Twenty-three more lives were lost in Thursday's report, up from 12 on Wednesday.

At a press conference earlier this week, Gov. Charlie Baker highlighted the state's efforts to be prepared in case of another surge of COVID-19.

Some say the governor's priorities are misplaced.

"To rely on a strategy that our health care system can respond and is sufficiently prepared to handle a surge simply means that we are sacrificing certain workers and certain communities who have much higher incidence of contracting COVID in order to have the economy remain open," said Carlene Pavlos of the Massachusetts Public Health Association. "And that's wrong. And it's also a terrible public health strategy."

Pavlos said the governor should instead focus on rolling back some of the measures that have allowed the economy to reopen.

"And that, for some people is certainly an economic hardship," she said. "And it's also something that if undertaken, should not be done lightly because it has serious implications. But when we are facing a surge, as we are here in Massachusetts and as we are in the country, we are going to need to prepare to take those kinds of steps to keep people safe."

For epidemiologist and infectious disease doctor Benjamin Linas of Boston University and Boston Medical Center, this week's testing results were particularly troubling.

"If it's the case that we're finding more COVID because we're simply doing more testing, we should be seeing the test positivity rate stay about the same or maybe even going down at the same time the cases are going up," Linas said. "But now what we're seeing is that the positivity rate is also going up at the same time that the cases are going up. And when that happens, it tells you you really have more COVID transmission going on in the community."

A new computer simulation suggests as many as 1,000 deaths could be prevented if Massachusetts were to implement stay-at-home orders.

The COVID-19 Policy Simulator — created by researchers at MGH, Harvard Medical School, Georgia Tech, and Boston Medical Center — predicts that with the current level of restrictions, there could be more than 800 new cases every day in Massachusetts. Under new stay-at-home orders, the computer model suggests the number of daily cases could be brought below 325.

The simulation indicates that without stay-at-home orders, the total deaths in Massachusetts could reach 12,000 by the end of the year. As of Thursday, 9,452 people in the state had died as a result of COVID-19.

Linas agreed with Pavlos that urgent action from the state is necessary to prevent a surge.

"Now is the time to act if we want to maintain a level of community spread that makes it possible to have some semblance of a holiday season in which we see friends and family, we need to act now," Linas said. "Because if we leave this unchecked, I think we could be back in a bad situation come late November and December when we really don't have the option and we need to be back into a stay-at-home situation."

But just where that action should be taken is an issue.

"What upsets me is that to the extent I have seen people talking, it's 'we're in the red, we can't open our schools,' which I find frustrating," Linas said. "I don't understand why the first thing that we want to close as soon as we have concern is our schools."

Linas said activities like school and work should be considered priorities.

"And where we should be seeking to control COVID is an activity like going out to eat," he said. "If we take those steps now, then maybe we can go back out and eat in a few weeks or months. But if we just continue on the course we're on now, I think we're going to end up most likely with a longer period of sacrifice than if we just address the issues that we see before us now while they still controllable and take action."

At Tuesday's press conference, Baker rejected the idea of closing restaurants.

"There's no evidence that that's that's driving our cases," he said. "I mean, I'm not going to stop doing things just because somebody doesn't like them. Somebody needs to actually demonstrate in our data that something is actually driving cases."

Baker instead pointed blame at the behavior of young people in the state.

"Not even necessarily college kids. We're talking kids who are out of college, who are spending a lot of time with each other in close quarters — apartments, rooftops, places like that. They're not social distancing. And they're passing the virus around."

That blame was echoed Thursday by Boston Mayor Marty Walsh, who said roughly half of the city's new COVID-19 cases are among people under 30 years old. Walsh said if people don't limit irresponsible behavior, he'll have to shut the city down again.