Mississippi’s doctors are calling for a statewide mask mandate after an increase in coronavirus cases that they say is hampering the ability of hospitals to provide emergency care for patients.

“We strongly believe that without a statewide mask mandate, our state’s healthcare system cannot sustain the trajectory of this outbreak, which could ultimately result in the loss of the lives of many Mississippians,” members of the Mississippi State Medical Association, representing more than 5,000 physicians, residents and medical students, wrote in a statement Tuesday.

Starting Monday, Mississippi Gov. Tate Reeves mandated that Mississippians in 13 of the state’s 82 counties must wear masks while in public places and while shopping in local businesses. The list includes the highly populated counties of Hinds, Madison, and Rankin, which have seen the greatest recent increases in new confirmed coronavirus cases.

The governor has said he could set the restrictions in more counties that are also seeing a rapid spread of cases, but he is still not planning a statewide mask requirement.

State Medical Association officials requested that Reeves reconsider. In their statement, they wrote that to overcome the public health crisis, state leaders need to let “evidence and science dictate our decisions and inform our actions.”

“Science and evidence have made it absolutely clear that COVID-19 is not behind us, and we must resist the urge to relax the measures that have proven effective in keeping people safe,” they wrote. “With the staggering toll of this pandemic on our state, we need to act quickly and decisively.”

Evidence has shown that masks and face coverings significantly reduce the spread of SARS-CoV-2, the virus that causes COVID-19, medical leaders said.

Mississippi has a population of about 3 million. The Health Department said Tuesday that the state has had at least 37,542 confirmed cases and at least 1,272 deaths from the coronavirus as of Sunday evening. That was an increase of 862 cases and 23 deaths from numbers reported the day before.

The department said at least 3,036 cases of the virus have been confirmed in long-term care facilities such as nursing homes, with at least 615 virus-related deaths in those facilities.

The true number of virus infections is thought to be far higher because many people have not been tested, and studies suggest people can be infected without feeling sick. While most people who contract the coronavirus recover after suffering only mild to moderate symptoms, it can be deadly for older patients and those with other health problems.