Citing the state's fastest increase in new coronavirus cases so far, Gov. Gavin Newsom on Monday pushed Kern and 38 other counties back into more restrictive reopening tiers, invoking what he called an "emergency break" meant to prevent the health care system from being overwhelmed.

The restrictions on businesses and other sectors take effect Tuesday, according to the governor's office. In Kern County, the move from the red to purple tier — the most restrictive — will mean that restaurants can only serve diners outside, and churches, gyms, movie theaters and museums may only conduct activities outdoors.

"Now is the time to do all we can — government at all levels and Californians across the state — to flatten the curve again as we have done before,” Newsom said in a news release.

Kern had been expected to move into the purple tier this week due to rising cases locally but affected sectors would normally have until Friday to come into compliance with restrictions. The reclassification announced Monday takes effect Tuesday and will remain in effect until further notice.

The California Department of Public Health is also now requiring everyone in the state to wear a face mask when outside their home except in limited situations. For example, individuals in a car alone or with members of their household, and people who are outside and can keep 6 feet of distance from others, don't have to wear a mask. Children age 2 and under are exempt from the mandate as are those with medical conditions that prevent them from wearing a mask, according to updated guidelines from CDPH.

“Personal decisions are critical, and I am imploring every Californian to stay home if they can, wear a mask whenever they leave their homes, limit mixing, practice physical distancing and wash their hands," said California Health and Human Services Secretary Dr. Mark Ghaly in the news release.

Kern County on Monday reported a seven-day average of 17.9 cases per 100,000 residents, up from 8.9 per 100,000 last week. Until now, counties had to have a case rate of less than 8 per 100,000 residents to be in the red tier. The seven-day average test positivity in Kern was 8 percent as of Monday, according to the state's data. Last week it was 5.2 percent.

The Kern County Superintendent of Schools sought to clarify that schools would remain open if some level of in-person instruction has resumed despite the county's move back to the purple tier. But a school site that has yet to reopen for in-person instruction must wait until the county moves back to the red tier to reopen, the office said in a news release.

Individual schools may be required to close, or to close a classroom, due to COVID-19 infections, KCSOS said. A classroom must be closed when there is one positive case in a classroom and a school must close if there are multiple classes or 5 percent of students and staff have confirmed cases. An entire school district must close when 25 percent of the schools within the district have closed due to COVID-19.

With the steep rise in cases, local doctors urged the public to reign in lax practices and return to the standard recommendations: wear masks, keep a distance of six feet from others and wash hands thoroughly and frequently.

"We have to go back to our due diligence. I think unfortunately moving back into the red tier sent this message that you don’t have to worry anymore," said Dr. Namisha Amin, a pediatrician with Southwest Pediatrics. 

Amin stressed the need for people to wear masks and to be cautious with their holiday plans. 

"I think now people can see masks work. We know because, look, our numbers came down, we moved out of purple we got to open up a little bit," she said. "It’s not that big of a request. It really does need to be everywhere."

Families will continue to face constant risk assessment about the safety of play dates, youth sports and sending kids to school, Amin said.

But when it comes to the holidays, Amin said, the safest things families can do is have Thanksgiving at home with household members and celebrate virtually with extended family.

For people who do plan to gather for the holidays, Dr. Paula Ardron, chief of allergy and immunology for Kaiser Permanente Kern County, said the limit should be 10 people and everyone should wear masks when not eating or drinking.

In particular, any guests coming into the household from out-of-town, including college students who may be returning home, should prompt the entire household to wear masks, she said.

"Because they haven't been in that bubble with you, you wear a mask and keep that six-foot distance," she said.

She advised against setting up a buffet-style meal, which is how COVID-19 spread so quickly on cruises early in the pandemic. Instead, one person should be the designated server, wearing gloves to dish out the food.

"That's the level of detail people need to think about when they're thinking about the holidays," she said.

Ardron also strongly encourages everyone to get a flu shot, especially since they can take two weeks to be effective.

While the move back to the purple tier may appear to be a setback, it's meant to quickly tamp down the spread of the virus, which is important, said Dr. Ronald Reynoso, chief medical officer for Adventist Health Bakersfield and Tehachapi.

"What you try not to do is get the big wave of disease like we had in the summer so we are in a position where we don’t get overwhelmed in our medical facilities," Reynoso said. "Because we’re humans taking care of humans so we have our limits. We don’t want our caretakers getting overwhelmed."