A timeline of Trump's musings on the false idea of injecting 'light' and 'disinfectant' to treat coronavirus — from a presentation to Trump's claim he was being 'sarcastic'

• At a press conference on Thursday night, US President Donald Trump, pondered, aloud, whether shining "very powerful light" inside the human body or injecting "disinfectant" could kill off the coronavirus.
• Trump said Friday that he was just being "sarcastic" when he mused about ingesting people with "light" and "disinfectant" to treat COVID-19.
• But earlier, Dr. Deborah Birx, White House coronavirus response coordinator, defended the comments. "When he gets new information he likes to talk that through," she told Fox News.
• The US Centers for Disease Control also reminded people on Friday that, "Household cleaners and disinfectants can cause health problems when not used properly."
• Here's a timeline of Trump's comments.
• Visit Business Insider's homepage for more stories.

At a press conference on Thursday night, President Donald Trump, pondered, aloud, whether shining "very powerful light" inside the human body or injecting "disinfectant" could kill off the coronavirus.

Here's a timeline of how Trump came to make this claim — and the subsequent fallout:

Wednesday, April 22: A study is reportedly presented to the White House task force on the coronavirus

According to a Friday report from The Washington Post, the Department of Homeland Security's acting undersecretary for science and technology, William Bryan, presented a study about the "possibility of heat, humidity, and light to kill the virus, as well as the effectiveness of disinfectants in killing it on surfaces" to the coronavirus task force.

A source told The Post that some on the task force, including White House coronavirus response coordinator Dr. Deborah Birx and National Institute of Allergy and Infectious Diseases Director Anthony Fauci, expressed their concerns about the study and/or its presentation. However, Vice President Mike Pence and others wanted Bryan to present the information at the briefing to give the public some good news, The Post reported.

Thursday, April 23: Before the White House press briefing

The Post reported that Bryan gave President Trump a "15-minute" presentation on the study ahead of the press briefing.

Bryan, The Post reported, was to present the study at the briefing, and Trump was to read prepared remarks.

Thursday, April 23: The briefing

Bryan presented the study, which focused on surfaces, not humans.

Trump, during his remarks, said the following, as transcribed by Business Insider's Grace Panetta:

During the presentation, Birx was caught on camera reacting to Trump's comments, and when asked by Trump about using heat and light to treat viruses she said: "Not as a treatment. I mean, certainly, fever is a good thing. When you have a fever, it helps your body respond. But I've not seen heat or light."

Thursday, April 23: After the briefing, the fallout begins

Some in the administration discouraged the thought. "No, I certainly wouldn't recommend the internal ingestion of a disinfectant," FDA Commissioner Stephen Hahn told CNN on Thursday night.

Doctors also began begging people not to ingest or inject disinfectants.

Friday, April 24: Companies and government agencies warn not to ingest or inject disinfectants, and the White House works to spin Trump's comments

By Friday morning, however, the president's spokesperson, Kayleigh McEnany, was claiming the comments were merely taken "out of context."

Birx, asked about the president's comments, told Fox News for a segment that is to air in full on Saturday, "When he gets new information he likes to talk that through, out loud, and really have that dialogue. And so that's what dialogue he was having."

By Friday afternoon, amid concern from medical professionals and ridicule from his critics, the president himself decided on a different approach: It had all been a joke, albeit an attempt at humor that no one seemed to get, Fox News included.

"I was asking a very sarcastic question to reporters in the room about disinfectants on the inside," Trump claimed.

The US Centers for Disease Control, meanwhile, wasn't taking any chances. "Household cleaners and disinfectants can cause health problems when not used properly," it tweeted early on Friday.

The makers of Lysol, too, said in a statement on Friday that "under no circumstance should our disinfectant products be administered into the human body (through injection, ingestion or any other route)."

Burger King also tweeted, "not sure why we need to be the ones to tell you this, but don't drink bleach."

And as Grace Panetta previously reported for Business Insider, "Maryland said its coronavirus hotline has received over 100 calls from people inquiring about President Trump's recent musings about ingesting disinfectant as a treatment for COVID-19."

At Friday evening's press briefing, neither Trump nor Pence took questions from the press.

As for the president's previously mused-about coronavirus treatment: The US Food and Drug Administration announced Friday that it is "aware of reports of serious heart rhythm problems in patients with COVID-19 treated with hydroxychloroquine or chloroquine."

Have a news tip? Email this reporter: cdavis@insider.com