Florida's main teachers union on Monday sued Governor Ron DeSantis and other authorities to stop schools from reopening in August, as the state has become a US epicenter of the COVID-19 pandemic.

The Florida Education Association, which represents 140,000 teachers, says the state constitution asserts that schools must provide a "safe and secure" environment, but that the COVID-19 resurgence "is remarkable and out of control."

Florida reported 10,347 new COVID-19 cases and 90 deaths on Monday, bringing the total death toll to 5,072.

More than 9,500 novel coronavirus patients have been hospitalized and just 18 percent of intensive care beds are available, officials say.

DeSantis "needs a reality check," said FEA President Fedrick Ingram. 

"Everyone wants schools to reopen, but we don't want to begin in-person teaching, face an explosion of cases and sickness, then be forced to return to distance learning," he said.

The lawsuit calls on DeSantis, state education commissioner Richard Corcoran and the mayor of Miami county to desist "from unnecessarily and unconstitutionally forcing millions of public-school students and employees to report to unsafe brick and mortar schools."

On July 6, Corcoran ordered schools to reopen for the academic year that begins in August, unleashing a tsunami of protests from parents, teachers and pediatricians.

DeSantis said that children have a low probability of contracting COVID-19, without mentioning that even asymptomatic children can infect adults.

He also said that he would have no problem sending his kids to school -- if he had school-age children.

- Demand for plasma -

The situation is so dire that DeSantis pleaded for COVID-19 survivors to donate blood plasma to help save lives, as supplies of antiviral drugs run short.

The governor, who has come under fire for his handling of the public health response and his opposition to ordering people to wear face masks, was interrupted by protesters chanting, "You're lying," as he made the appeal at the OneBlood donor center in Orlando.

Raising his voice over activists banging at the door, DeSantis called on Floridians to take tests for antibodies and to donate plasma if they test positive.

"There are people that had this with no symptoms a month or two ago that will have antibodies that can be used for this," the Republican governor said.

Lines of people hoping to get tested, however, can stretch for almost a mile, and the results take seven to 10 days to come back, during which time contagious people can easily infect others.

Plasma transfers have shown encouraging results in hospital patients, as the so-called "convalescent plasma" can be used to help infected people develop antibodies that stay in their own blood.

"The demand is currently unprecedented, it's a revolving door," said OneBlood president George Scholl. 

"As quickly as the plasma comes in, it goes back out because that is the importance of the need," he said.