NATIONWIDE — As the Trump administration pushes full steam ahead to force schools to resume in-person education, public health experts warn that a one-size-fits-all reopening could drive infection and death rates even higher.

They’re urging a more cautious approach, which many local governments and school districts are already pursuing.

But U.S. Education Secretary Betsy DeVos doubled down on President Donald Trump’s insistence that kids can safely return to the classroom.

“There’s nothing in the data that suggests that kids being in school is in any way dangerous,” she told Chris Wallace on “Fox News Sunday.”

Still, heath experts say there are too many uncertainties and variables for back-to-school to be back-to-normal.

Where is the virus spreading rapidly? Do students live with aged grandparents? Do teachers have high-risk health conditions that would make online teaching safest? Do infected children easily spread COVID-19 to each other and to adults?

Regarding the latter, some evidence suggests they don’t, but a big government study aims to find better proof. Results won’t be available before the fall, and some schools are slated to reopen in just a few weeks.

“These are complicated issues. You can’t just charge straight ahead,” Dr. Tom Frieden, former director of the Centers for Disease Control and Prevention, said Wednesday during an online briefing.

Children infected with coronavirus are more likely than adults to have mild illnesses, but their risk for severe disease and death isn’t zero. While a virus-linked inflammatory condition is uncommon, most children who develop it require intensive care, and a few have died. Doctors don’t know which children are at risk.

“The single most important thing we can do to keep our schools safe has nothing to do with what happens in school. It’s how well we control COVID-19 in the community,” Frieden said. “Right now there are places around the country where the virus is spreading explosively and it would be difficult if not impossible to operate schools safely until the virus is under better control.”

Zahrah Wattier teaches high school in Galveston, Texas, where cases and deaths have been spiking. Until the state recently said schools must reopen to in-person classes, her district had been weighing options many others are considering, including full-time online teaching or a hybrid mix.

Wattier’s school has mostly Hispanic and Black students, many from low-income families; almost 70% qualify for free or reduced-cost lunches and many have parents who work in “essential” jobs that increase potential exposure to the virus. Online education was hard for many with limited internet access, and Wattier knows in-person classes can help even the playing field.

But she’s worried.

“My school has over 2,000 students. That’s over 2,000 exposures in a day,” said Wattier, whose parent live with the family and are both high-risk. “It’s a lot to think about. It’s my job. It’s something I choose to do, it’s something I love. Now it comes at a really high risk.”

The American Academy of Pediatrics, whose guidance the Trump administration has cited to support its demands, says the goal is for all students to be physically present in school. But, it adds, districts must be flexible, consult with health authorities and be ready to pivot as virus activity waxes and wanes.

“It is not that the American Academy of Pediatrics thinks this is a done deal because we have put out guidance,” said Dr. Nicholas Beers, a member of the academy’s school health council. “But what we do know is that we need to have a more realistic dialogue about the implications of virtual learning on the future of children. We have left whole swaths of society behind, whether it’s because they have limited access to a computer, or broadband internet,” or because of other challenges that online education can’t address.

DeVos said local school officials are smart enough to know when conditions are not right.

“There’s going to be the exception to the rule, but the rule should be that kids go back to school this fall,” she told CNN’s “State of the Union.”

“And where there are little flare-ups or hot spots, that can be dealt with on a school by school or a case by case basis.”

Following CDC and academy guidelines would mean big changes for most schools. Mask-wearing would be strongly encouraged for adult staff and students except the youngest. Desks would be distanced at least 3 feet apart; the CDC recommends 6 feet. Both suggest limiting adults allowed in schools, including parents, and canceling group activities like choir and assemblies. Staggered arrival and dismissal times, outdoor classes, and keeping kids in the same classroom all day are other options.

President Trump has threatened federal funding cuts for districts that don’t fully reopen.

DeVos defended that stance, saying, “American investment in education is a promise to students and their families.”

“If schools aren’t going to reopen and not fulfill that promise, they shouldn’t get the funds, and give it to the families to decide to go to a school that is going to meet that promise,” she said on “Fox News Sunday.”

U.S. House Speaker Nanci Pelosi called DeVos’ comments “malfeasance and dereliction of duty.”

“They’re messing, the president and his administration are messing with the health of our children,” the California Democrat told CNN’s “State of the Union.”

While most funding typically comes from state and local sources, experts say schools will need more federal funding, not less, to reopen safely. Masks, extra cleaning supplies or janitors, additional classroom space, mental health support for students and staff traumatized by the pandemic are among potential costs. And with more parents out of work, more children will qualify for federally funded school lunches.