COVID-19 updates: 345 children currently hospitalized with coronavirus in Texas

The mayor of Stillwater, Oklahoma, declared a state of emergency for the city that started Friday due to a soaring number of hospital patients and a shortage of medical staff. 

Overflow tents have been set up outside the Stillwater Medical Center Emergency Department to deal with the influx. 

The state’s department of health is deploying the Medical Reserve Corps. and additional medical professionals to help in overflow tents.

“Our health professionals have incessantly warned us that we may reach the point when much-needed medical attention, COVID or non-COVID related, may not be available,” Mayor Will Joyce said in a release. “We have now reached that critical threshold where our hospital no longer has available staffed beds.”

“It is critical that each of us become fully vaccinated against COVID-19 and wear masks when possible,” he added.

Officials said Stillwater Medical, which serves in a six-county area, is at full capacity. 

In the crisis, residents and visitors who go to the hospital for treatment over the weekend may be diverted to nearby or out-of-state facilities. 

There are zero ICU beds available across the four largest hospital systems in Oklahoma City, ABC local affiliate in Oklahoma City KOCO reported. 

Concerns are mounting especially as Stillwater hosts events and activities that kick off Saturday and have the potential to attract an influx of 40,000 visitors.

Hall of Fame boxer Oscar De La Hoya said on social media Friday he is hospitalized with COVID-19.

Due to his illness, he won't be able to fight former UFC champion Vitor Belfort on Sept. 11 in Los Angeles, which would have been De La Hoya's first bout since 2008. 

"Preparing for this comeback has been everything to me over the last months, and I want to thank everyone for their tremendous support," De La Hoya, 48, said in an Instagram post, noting that he is fully vaccinated. "I am currently in the hospital getting treatment and am confident I will be back in the ring before the year is up. God bless everyone and stay safe."

Florida Gov. Ron DeSantis filed an appeal against a court ruling invalidating his ban on student mask mandates Thursday evening.

The governor had banned school districts from implementing mask mandates without a parent opt-out. 

The move unleashed a stay of proceedings that enables the state to continue punishing districts, at least until Wednesday, when a judge will decide whether to vacate the stay. 

In the meantime, school board members across the state could continue to lose their salaries if their schools set mask mandates -- a punishment given to board members in two counties and threatened to those in eight others.

The appeal comes a week after Judge John C. Cooper found that a blanket ban on face masks in schools "does not meet constitutional muster.”

-ABC News' Will McDuffie

The country’s COVID death toll has risen to more than 643,000 and the number of cases stands at 39.5 million, according to data from Johns Hopkins University.

That means 1 out of 8 Americans has tested positive for COVID-19 and 1 out of 510 Americans has died of the virus. 

Heading into Labor Day weekend health experts are urging the public, especially the unvaccinated, to act responsibly as the delta variant continues to fuel infections. 

Holidays have proven to be a catalyst for virus spread in the U.S. 

Last summer, shortly after Labor Day, the U.S. fell into its most significant viral surge of the pandemic. 

Between the week following last Labor Day and Thanksgiving alone, the nation's daily case average surged by more than 400%.

-ABC News' Arielle Mitropoulos