BOSTON — In a matter of "weeks and months," as many as 172,000 Massachusetts residents could become infected with the coronavirus and the surge of COVID-19 patients hospitals have been preparing for is now expected to hit sometime between April 10 and April 20, Gov. Charlie Baker said Thursday afternoon.

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The new projections are the result of a model put together over the last several weeks by public health experts, health care providers, academics and others. The governor detailed the information gleaned from the model in-depth for the first time Thursday.

"We estimate at this point in time that the number of confirmed cases of COVID-19 in Massachusetts will range somewhere between 47,000 and 172,000 cases during the course of the pandemic. That's about 0.7 percent to two-and-a-half percent of the total population in Massachusetts, and at this time the modeling indicates that hospitalizations would potentially peak between April 10 and April 20," Baker said. "The current fatality rate in Massachusetts is lower than in many other parts of the country in the world, currently running at approximately one-and-a-half percent of those infected."

If the current fatality rate were to hold, the range of infections Baker gave Thursday could be expected to lead to between 705 and 2,580 COVID-19 deaths in the Bay State. As of Thursday afternoon, Massachusetts has reported 8,966 confirmed COVID-19 cases and 154 deaths, while more than 5,000 people are officially under quarantine while they're monitored for symptoms. Public health officials reported 32 deaths Thursday afternoon.

The model is based on data and experiences in Wuhan, China, where the virus originated, Baker said. He noted that there are several important differences between Wuhan and Massachusetts -- including a lower population density here, a lower smoking rate and strict social distancing measures enacted sooner -- and said "we do anticipate Massachusetts trajectory could differ for" those reasons and others.

"We know all models are not perfect, but obviously you need to plan for the worst and at the end of the day hope you do not need to go that far," the governor said.

Part of the planning process in recent weeks has been working with hospitals to implement surge plans under which they could expand their intensive care unit capacity. Baker said Health and Human Services Secretary Marylou Sudders and others in his administration have been working on those plans with hospitals and the Massachusetts Health and Hospital Association "for several weeks, so that we all are basically working off a similar playbook with respect to what's required to meet the projected need." And there is a projected need.

"We believe that after hospitals execute on their surge plans -- that is, what they believe they need to do with their current resources to add beds, staff and equipment -- more beds will still be needed for both intensive care and for acute care here in Massachusetts," Baker said. "And based on our projections, we believe we need to expand capacity of ICU beds by approximately 500 beds in the coming weeks."

To reduce the strain on hospitals, the state has been actively setting up field hospitals that can treat lower acuity patients who need to be monitored, but don't necessarily need to be in a physical hospital. Baker toured the first such facility Wednesday at Worcester's DCU Center. Additional field hospitals -- the goal is to create another 750 to 1,000 beds -- could be set up at the Boston Convention & Exhibition Center, Joint Base Cape Cod, Springfield's Mass Mutual Building and other smaller locations. The governor said the state has secured a contractor to build the facilities once a health care partner has been finalized.

Massachusetts also needs more ventilators, a piece of medical equipment that becomes essential for patients hit hardest by COVID-19. Baker said "we know we need more ventilators," but did not offer an estimate of the need. Earlier this week, the governor announced that the federal government would be sending more than 1,000 ventilators to Massachusetts. He said Monday that he expected the ventilators to arrive by the end of the week.

But between Monday and Thursday, things changed. Instead of requesting 1,000 ventilators, the state revised its ask on Thursday and is now seeking 1,400 ventilators, Sudders said. The state has not yet received any ventilators from the national stockpile and Baker said Thursday that he no longer expects they will arrive by the end of the week.

"The big thing the feds are trying to figure out at this point -- and I'm mildly sympathetic to them on this one -- is where they think the next big opportunity or the next big surge is going to be so that they make sure they deliver sort of just in time," Baker said. "They don't want to be putting them out to people long before they're actually going to be necessary or put into use."

Whenever ventilators arrive, Sudders said, they will immediately be sent to hospitals for testing and that a panel of medical experts is being put together to determine how those ventilators should be allocated to facilities around the state.

As Baker spoke Thursday, a plane owned by the New England Patriots was en route to Logan International Airport, loaded with more than 1.2 million N95 masks for New England and New York health care workers to protect themselves as they care for COVID-19 patients and fight the coronavirus pandemic. Baker, Lt. Gov. Karyn Polito and members of the Kraft Family planned to be there for the 6:30 p.m. arrival at Delta Hangar.

The shipment of personal protective equipment was the result of a weekslong quest and the work of Baker and the Kraft family. Baker said Thursday that "nearly one million" of the masks will go to front-line workers in Massachusetts.

"This was a collaboration between U.S. and Chinese government and private sector folks, and required a lot of support from many entities and agencies along the way. We're grateful that the Patriots plane was able to land in China, load up and return quickly to the U.S. I also want to thank the People's Republic of China for going to the lengths they went to to make this humanitarian aid trip possible."

Masks are a critical piece of personal protective equipment for hospital workers and though the shipment secured with the help of the Patriots will help, Baker said it still will not be enough. To try to extend the useful life of each mask, Partners HealthCare is setting up an N95 mask decontamination center in Somerville.

Sudders announced that Partners had secured a Battelle N95 decontamination system, which can decontaminate up to 80,000 of the masks each day, and plans to have it up and running at a vacant KMart site in Somerville by Monday. Sudders said decontaminating 80,000 masks a day "should cover all demand in Massachusetts over time." She said each mask could be decontaminated five to 10 times before it has to be discarded.

"You combine that shipment with the machine Secretary Sudders talked about and while we will never have enough gear -- we are always going to be seeking gear, we have a huge pipeline of additional asks and potential orders and all the rest -- ... this gives us the thing we have heard time and time again from first responders and emergency medics medical personnel and nurses and docs and everybody else on the health care side, which is N95 gear. And the fact that we'll be able to decontaminate it and use it on an extended basis using an FDA-approved machine that will be located right here in Massachusetts creates a shelf life for that equipment."

Once the masks are unloaded from the plane, Sudders said they will be taken to a state warehouse, inventoried and prepared for distribution. She said the state plans to first distribute the gear to facilities that have five days worth of gear or fewer first. Allocations will be based on each facility's likelihood of exposure.

"So it's hospitals, nursing homes, EMS, fire, police, schools and then other agencies. That's just sort of the hierarchy of how we will distribute it from, again, from who needs N95 in terms of the highest likelihood of COVID-19 exposure to the lower likelihood," Sudders said.

The state will also begin reporting data on PPE distribution, Sudders said, so the public knows where the critical gear is being delivered.

At the start of his press conference, Baker acknowledged that the social distancing measures put in place over the last few weeks have been "extremely hard" and have changed how everyone lives their life. But, he said, those steps are crucial to putting Massachusetts in a better position to be able to handle the approaching COVID-19 surge.

"The next three to four weeks are going to be very difficult ones," he said. "We're supposed to do everything we possibly can to limit our exposure to other people. This virus can't survive if it can't jump from one person to the next."