WASHINGTON — After a presentation Thursday that touched on the disinfectants that can kill the novel coronavirus on surfaces and in the air, President Donald Trump pondered whether those chemicals could be used to fight the virus inside the human body.

"I see the disinfectant that knocks it out in a minute, one minute," Trump said during Thursday's coronavirus press briefing. "And is there a way we can do something like that by injection inside, or almost a cleaning? Because you see it gets inside the lungs and it does a tremendous number on the lungs, so it would be interesting to check that."

The question, which Trump offered unprompted, immediately spurred doctors to respond with incredulity and warnings against injecting or otherwise ingesting disinfectants, which are highly toxic.

"My concern is that people will die. People will think this is a good idea," Craig Spencer, director of global health in emergency medicine at New York-Presbyterian/Columbia University Medical Center, told The Washington Post. "This is not willy-nilly, off-the-cuff, maybe-this-will-work advice. This is dangerous."

In a statement Friday, White House press secretary Kayleigh McEnany noted that Trump had said Americans should consult with their doctors about treatment. She accused the media of taking his words out of context.

"President Trump has repeatedly said that Americans should consult with medical doctors regarding coronavirus treatment, a point that he emphasized again during yesterday's briefing," she said.

Trump's eyebrow-raising query came immediately after William Bryan, the acting undersecretary for science and technology at the Department of Homeland Security, gave a presentation on the potential impact of summer heat and humidity, which also included references to tests that showed the effectiveness of different types of disinfectants. He recounted data from recent tests that showed how bleach, alcohol and sunlight could kill the coronavirus on surfaces.

Bryan said bleach killed the virus in about five minutes and isopropyl alcohol killed it in 30 seconds. In tests, sunlight and high temperatures also appeared to shorten the virus's life on surfaces and in the air, Bryan said.

Trump previously has claimed that the arrival of summer weather will help fight the coronavirus outbreak without resorting to aggressive social distancing measures that carry significant economic ramifications. The study Bryan presented Thursday appeared to back those claims to some degree, although its results have not been peer-reviewed.

As Bryan left the podium without answering reporters' questions, Trump stepped up to the mic. Before he allowed anyone to ask a question, the president offered an answer to a "question that, probably, some of you are thinking of if you are totally into that world, which I find to be very interesting."

That's when he asked about injecting an unspecified disinfectant into the lungs of COVID-19 patients. He also raised the possibility of using light to combat the viral infection and suggested consulting medical doctors with these questions.

"So, supposing we hit the body with a tremendous, whether it's ultraviolet or just very powerful light — and I think you said that hasn't been checked but you're going to test it," Trump said to Bryan. "And then I said supposing you brought the light inside the body, which you can do either through the skin or in some other way."

He continued: "And I think you said you're going to test that, too. Sounds interesting."

As president spoke, one of his top public health experts, Deborah Birx, the response coordinator for the White House's coronavirus task force, listened in a chair a few feet away from the podium.

Birx did not immediately respond to Trump's remarks about light therapy or disinfectant injections at the coronavirus briefing. Instead, she watched silently from the sidelines, her lips pressed in a tight line as Trump riffed on testing the unproven treatments.

Later in the briefing, Trump turned to Birx and asked if she had any knowledge of heat or light being used as a potential treatment for COVID-19.

"Not as a treatment," Birx answered from her seat. "I mean, certainly fever is a good thing. When you have a fever, it helps your body respond." Then Trump started talking again, cutting her answer short.

Other doctors stepped forward after the briefing to challenge the president, calling his comments "irresponsible," "extremely dangerous" and "frightening" in interviews with The Post as they rushed to warn people of the dire consequences of ingesting caustic chemicals.

"We've heard the president trying to practice medicine for several weeks now, but this is a new low that is outside the realms of common sense or plausibility," said Ryan Marino, a medical toxicologist and emergency physician at University Hospitals in Cleveland.

"I can understand looking to medicines that might have some effect or some sort of studies in a petri dish showing that they might work on a virus," Marino added. "But talking about putting ultraviolet radiation inside of the human body or putting antiseptic things that are toxic to life inside of living people, it doesn't make any sense anymore."

And not only were Trump's statements baffling, doctors told The Post that his remarks could pose risks to the lives of those who interpret the words as a suggestion to try the unproven treatments themselves.

"People will do extraordinary things if you give them the idea," said Dara Kass, associate professor of emergency medicine at Columbia University Medical Center.

Even before the president's musings, a Centers for Disease Control and Prevention report released Monday found U.S. poison control centers were seeing a surge in calls about exposure to cleaners and disinfectants amid the coronavirus outbreak. Between January and March, there were 45,550 calls — a 20.4% increase from the same period last year.

The CDC called for consumers to "always read and follow directions on the label," avoid mixing chemical products, ensure adequate ventilation and store chemicals out of the reach of children.

Some doctors likened Trump's comments on disinfectants to his past remarks about chloroquine and hydroxychloroquine, antiviral drugs that are used to treat malaria and are being tested to determine whether they might assist in treating COVID-19. One recent study found the drugs were linked to higher death rates in coronavirus patients, The Post reported, and other clinical trials are still underway. But Trump had touted the drugs as a "game changer" before evidence from early trials had come back, encouraging people to get prescriptions and try the medicines.

But Trump's Thursday musings have the potential to cause even greater harm, Kass said to The Post.

"The difference between this and the chloroquine is that somebody could go right away to their pantry and start swallowing bleach. They could go to their medicine cabinet and swallow isopropyl alcohol," Kass said. "A lot of people have that in their homes. There's an immediate opportunity to react."

People who ingest such chemicals often die, Kass said. Those who survive usually end up with feeding tubes, a result of their mouth and esophagus being eroded by the cleaning agents.

"It's horrific," she said.

By late Thursday, social media was flooded with pointed warnings from doctors, begging people not to attempt self-medication amid the pandemic.

On CNN, Food and Drug Administration Commissioner Stephen Hahn said he believes the president's comments reflect a question "many Americans are asking," but cautioned people not to consume disinfectants at home.

"We certainly wouldn't want, as a physician, someone to take matters into their own hands," Hahn said. "I think this is something a patient would want to talk to their physician about, and no, I certainly wouldn't recommend the internal ingestion of a disinfectant."

Former FDA Commissioner Scott Gottlieb also weighed in, warning of potential outcomes including death.

"Well, look I think we need to speak very clearly that there's no circumstance in which you should take a disinfectant or inject a disinfectant for the treatment of anything, and certainly not for the treatment of coronavirus," he said Friday on CNBC's Squawk Box. "There's absolutely no circumstance in which that's appropriate, and it can cause death and very adverse outcomes."

Trump's remarks even prompted the maker of Lysol and Dettol to urge people not to ingest disinfectant as many essential household cleaning products trended on Twitter well into Friday morning.

"We must be clear that under no circumstance should our disinfectant products be administered into the human body (through injection, ingestion or any other route)," the Reckitt Benckiser Group said in an email to The Post on Friday. "With all products, our disinfectant and hygiene products should only be used as intended and in line with usage guidelines. Please read the label and safety information."

Some lawmakers also expressed alarm. During an NPR interview on Friday morning, Senate Minority Leader Charles Schumer, D-N.Y., described the president as "a quack medicine salesman."

"We seem to have a quack medicine salesman on television," he said. "He's talking about things like disinfectant in the lungs."

The senator added: "We need real focus in the White House on what needs to be done. Instead of talking about disinfectant the president should be talking about how he's going to implement testing, which every expert says is the quickest path to get us moving again."

Meanwhile, experts also sought to fact-check Trump's claims about light as a possible treatment.

“No, you cannot inject UV light into your body to cure #COVID19 — neither biology or physics work that way,” tweeted science writer David Robert Grimes, who noted that he earned his PhD in medical ultraviolet radiation.

Still, despite the prolific warnings, doctors told The Post not everyone is going to listen.

"There is an emergency department in America in the week that will probably get a bleach ingestion because of this," Kass said. "We know that because people are scared and vulnerable, and they're not going to think it's that dangerous because they can get it in their house."

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The Washington Post’s Jennifer Hassan contributed to this report.