California Gov. Gavin Newsom implored people Monday to wear face coverings to protect against the coronavirus and allow businesses to safely open after several days in which the state saw its highest virus hospitalizations and number of infections to date.

In a bid to reach not only supporters but also his critics, Newsom released a video campaign promoting the use of masks featuring Arnold Schwarzenegger and three other former California governors. Taking off his mask as he began his press briefing, Newsom touted the importance of opening businesses to ensure the health of California’s economy while warning that if health conditions grow dire, the state could be forced to shut them back down.

“We don’t intend to do that, we don’t want to do that,” Newsom said. “But I want to make this clear we are prepared to do that if we must.”

California is trying to balance the need to reopen businesses and sustain the livelihood of its nearly 40 million people while simultaneously protecting them from the virus. In recent weeks, the state released detailed guidelines for how settings ranging from fitness centers and day camps to restaurants and museums can do so safely, but last week imposed a new mask requirement that Newsom said takes precedence over the earlier recommendations.

Californians are now required to wear facial coverings in most indoor settings and outdoors when it’s not possible to stay 6 feet (1.8 meters) apart. There are exceptions for children ages 2 and under and people with health conditions.

The change comes as new cases and hospitalizations rise. The number of people hospitalized with the coronavirus in California has inched up each of the past three days and now hovers above 3,700, the highest rate since Newsom ordered Californians to stay home in mid-March. While the state now has ample capacity to handle more patients, it’s a reminder, the governor said, that “we are still in the first wave of this pandemic.”

On Monday, the Assembly’s rules committee announced that a statehouse staffer had tested positive for the coronavirus. The employee, who worked at a Capitol office suite last week, had limited contact with a co-worker and wore a mask and is complying with federal quarantine recommendations, said a memo from the chamber’s chief administrative officer.

Masks have become a flash point in many parts of California where some residents demand they be worn to protect their safety while others refuse, saying the requirement violates their personal freedom.

Over the weekend, police officers in Turlock escorted a shopper and his two unmasked children out of a Walmart when they refused to wear face coverings and were asked to leave by the store, the East Bay Times reported. In heavily populated counties including Orange and Riverside, sheriffs have said they don’t plan to enforce mask rules.

Public health officials have faced criticism and threats since the pandemic. Orange County’s former health officer quit after receiving threats over a mask rule. On Monday, Los Angeles County Public Health Director Barbara Ferrer said the hatred and daily threats of violence against herself and public health officials is worrisome and disheartening.

“The virus has changed our world as we know it, and people are angry,” Ferrer said in a statement that recounted how someone casually suggested during a Facebook Live briefing that she should be shot. “And while frustration boils over in our communities as people are done with this virus, this virus is not done with us.”

Newsom said the goal was to educate people so they will choose to wear facial coverings, not punish them, but also suggested Californians should report businesses that are not complying with the safety guidance.

“When you go to a restaurant and it’s clear they are not practicing what we are preaching, report that,” he said.

Federal and state health officials have recommended wearing facial coverings because the coronavirus spreads through tiny droplets emitted when people speak or cough. For most people, the virus causes mild or moderate symptoms. But for some, especially older adults and people with existing health problems, it can cause pneumonia and death.

In the PSA released Monday, the former governors — two Republicans and two Democrats — convey their understanding that nobody wants to wear masks, but COVID-19 is still spreading and halting it is important to keeping people safe, reopening businesses and putting people back to work.

“Just do it,” Schwarzenegger says.