Health officials in Riverside County, California, are recommending the widespread use of masks in public to help flatten the curve of the novel coronavirus, according to a press release sent on Tuesday.

County health officials are urging residents of Riverside County to cover their nose and mouth “anytime a person is outside of their home, even in offices of essential businesses.” Officials say the masks do not have to be medical grade and suggest bandanas and fabric masks as acceptable alternatives.

The county had 371 confirmed cases of the virus as of Tuesday and 13 related deaths.

“When the situation changes, the rulebook changes,” Dr. Cameron Kaiser, Riverside County public health officer said in a statement, reminding residents that the additional recommendation of a mask does not change social distancing orders.

“We’re seeing our numbers increasing even sooner than we predicted and that means our strategy must change too,” Kaiser said.

“Covering your face doesn’t change the orders everyone must abide by to stay home as much as possible and maintain social distancing, but it’s an extra layer of protection that I think we need to add,” he added.

Per the press release:

The rationale for covering one’s face comes from the belief that transmission occurs primarily through droplets from an infected individual, which fabrics can easily filter. This not only helps to reduce the risk a well person can breathe those droplets in, but also protects others around someone with mild symptoms who may not yet realize they have the illness. Face covering should be worn anytime a person is outside of their home, even in offices of essential businesses.

Board Chair V. Manuel Perez, Fourth District Supervisor, said in a statement that, in order to flatten the curve, “another layer of aggressive protection against the virus” is needed.

“Please take the additional steps to cover your face,” Perez added.

The county health officials’ recommendation comes as both the CDC and President Trump’s coronavirus task force weigh issuing a similar widespread recommendation.

“The thing that has inhibited that a bit is to make sure that we don’t take away the supply of masks from the health-care workers who need them,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told CNN this week.

“But when we get in a situation when we have enough masks, I believe there will be some very serious consideration about broadening this recommendation of using masks,” he added. “We’re not there yet, but we’re close.”

US Surgeon General Dr. Jerome Adams also said the administration is asking the CDC to review its current guidance, or lack thereof, on masks.

“Now we’ve learned about this disease … and we’ve learned there’s a fair amount of asymptomatic spread and so we’ve asked the CDC to take another look at whether or not having more people wear masks will prevent transmission of the disease to other people,” Adams said during an appearance on Wednesday’s Good Morning America.