As coronavirus picks up steam in the U.S., Ohio Governor Mike DeWine announced the state would close down all its bars and restaurants Sunday night — to keep people from infecting one another.

This is a potent social distancing measure, which means keeping at least three feet away from someone, or avoiding crowds. Infectious disease experts, including those who have helped stamp out deadly epidemics before, say social distancing is imperative to slow the inevitable spread of coronavirus, which results in the respiratory disease COVID-19.

"We will be issuing an order closing all bars and restaurants in #Ohio beginning at 9:00 tonight," DeWine, a Republican, tweeted on Sunday afternoon.

"Every day we delay, more people will die," DeWine continued. "If we do not act and get some distance between people, our healthcare system in #Ohio will not hold up. The loss won't only be those impacted by #COVID19, but the danger is also to everyone else who needs hospital care for other issues."

(Illinois, meanwhile, announced on Sunday that it will close "inside dining" for two weeks.)

Establishments can stay open for carry-out and delivery. What we can't have is people congregating and seated. #COVID19 #COVID19OhioReady pic.twitter.com/3EaBWeeMdr — Governor Mike DeWine (@GovMikeDeWine) March 15, 2020

DeWine's effort intends to reduce strain on hospitals — which can't care for the coming rise in severely sick people, particularly folks over 60. Ohioans can still get their restaurant-fix via takeout, and buy beer from stores.

Due to a woeful lack of testing in the U.S., it's still unknown how many people are infected with coronavirus, but top epidemiologists know the number is "much higher" than just the reported cases. There are over 3,200 confirmed cases so far in the U.S., according to Johns Hopkins University, with 37 confirmed in Ohio.

The glaring problem with bars is that coronavirus doesn't make people sick quickly. So people show up to socialize unaware they're infected. Around 80 percent of us experience milder symptoms — or no symptoms at all. People might not even know they're sick for some five days.

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"That person is flying, walking, and interacting," said Mark Cameron, one of the scientists who contained the 2003 SARS outbreak in Canada. "They're spreading the virus without realizing they’re sick."

So with this bug, now a pandemic, social distancing is critical.

"Social distancing goes a long way to prevent the rapid spread of the virus," Akiko Iwasaki, a professor of immunobiology at the Yale School of Medicine, told Mashable last week.