By Holly Yan and Madeline Holcombe, CNN

(CNN) -- No one wants another shutdown. But Americans who don't wear masks and ignore social distancing are fueling that possibility, doctors say.

"We are breaking records all over the place here. The rate of acceleration of this virus is just increasing," emergency medicine physician Dr. Leana Wen said.

"We're already seeing our hospitals at breaking point in some parts of the country. And that means it doesn't just affect patients with coronavirus. It also means that elective surgeries are being put off for things like hip replacements, for cancer surgery or heart surgery in some cases," she said.

"When we get to breaking point here, we might have no other choice but to implement these measures that no one wants, like shutdowns. And that's why we all have to take action right now with targeted measures, like wearing masks, like restricting indoor gatherings -- things we can do now to prevent that really horrible outcome because cases are raging out of control across the US."

Nationwide, the pandemic has gone from bad to worse.

The US just set a new record for the highest seven-day average of daily new cases: 81,336 as of Sunday. That's the first time the number has ever topped 80,000, according to data from Johns Hopkins University.

And once again, new cases are far exceeding new testing. Over the past week, new cases have increased 18%, according to Johns Hopkins. But the number of new tests performed has increased only 4.29%, according to the Covid Tracking Project.

Why this surge is so different from the others

"The difference between what's happening now vs. what happened before is that the virus is everywhere now," Wen said.

"Before, there were just a few hotspots across the country. There were health care workers who could volunteer and go between different states," she said.

"But when the virus is so widespread, we could very well ... run out of health care workers, which means that patient care is going to suffer. And we will be at breaking point in our hospitals."

Hospitalizations are the best measure of how the nation is faring against the pandemic. And surges in hospitalizations often lead to more deaths in the following weeks, said Dr. Christopher Murray, director of the University of Washington's Institute for Health Metrics and Evaluation.

Wen said she's particularly worried about rural hospitals, some of which are "already unable to transfer patients to higher levels of care and may even be transferring their patients with heart attacks or strokes hundreds of miles away."

The five states with the highest test positivity rates Monday are all in rural areas of the US -- South Dakota (50%), Wyoming (43%), Iowa (36%), Idaho (34%), and Kansas (34%).

To put those rates in perspective, the World Health Organization has recommended governments stay at or below a 5% test positivity rate for at least 14 days before reopening.

But as of Monday, 36 states and Puerto Rico have exceeded that 5% threshold, according to Johns Hopkins.

All this comes after the highest-ever number of new cases reported anywhere in the world. On Friday, the US set the new global record of new cases in one day -- 99,321.

The rapid acceleration has even stunned health experts.

"I was predicting just a week or two ago we'd hit 100,000 (new cases a day). I didn't imagine it would be already there," said William Haseltine, a former Harvard Medical School professor and chair of ACCESS Health International.

"This pandemic is really rolling out of control, and we can change the trajectory. People know how to change it. Things as simple as universal mask wearing, social distancing, closing bars, stopping big rallies can make a big difference."

He said the US doesn't have to endure more shutdowns if everyone uses personal responsibility to put a lid on this pandemic.

"This is something we have to control and we can control, through our behavior," said Haseltine.

More than 9.2 million people across the US have been infected with coronavirus, and more than 231,000 have died.

El Paso is preparing a third mobile morgue

In Texas, officials in the El Paso area are preparing to add a third mobile morgue as hospitalizations skyrocket.

The number of people hospitalized due to Covid-19 in El Paso has reached an all-time high of 943 patients.

The extra morgues are a grim reminder of how serious this pandemic is, El Paso County Judge Ricardo Samaniego wrote on Facebook.

"If that doesn't put our situation into perspective, I don't know what will," he said.

Concerns about vaccine distribution

Health experts say a vaccine probably won't be widely available to the American public until mid-2021. But there are already some concerns about how vaccines will be distributed.

On Sunday, New York Gov. Andrew Cuomo criticized the Trump administration's vaccine distribution plan. He said the plan, as explained to him by the White House, involves the military distributing a future Covid-19 vaccine to large pharmacy chains for distribution.

"Why was the Covid infection rate so much higher in communities of Black and brown people? Because they're health-care deserts," the governor said.

The Department of Health and Human Services said in September that it will coordinate with the Department of Defense and the US Centers for Disease Control and Prevention on the delivery of vaccine supplies.

Cuomo called on the administration to conduct specific vaccine outreach in underserved communities, and to give states funding to develop their own such programs.

New York state was once the epicenter of Covid-19 in the US, but managed to drive its numbers down after drastic mitigation efforts.

New York now has the third-lowest test positivity rate of any state in the country -- 1.54% as of Monday.

"New Yorkers should be very proud of that fact," Cuomo said, "But we also need to remain vigilant."