An emergency room doctor posted a Twitter thread saying the country cannot “waste our energy” on those who do not wear masks during the COVID-19 pandemic.

Cleavon Gilman uses the Twitter handle Cleavon MD and posted a 15-second video credited to an NBC reporter that showed people not wearing masks in a Naples, Florida, supermarket. He commented, “Naples, Florida. Let’em die. I’m so tired of these people. No vaccines for y’all.”

The comments generated backlash, with some responses suggesting the doctor should lose his medical license. Others backed him up, saying those protesting mask mandates should sign forms waiving emergency medical care.

He took on one critic in a follow-up Tweet, saying, “When you don’t wear a mask, refuse to socially distance and get infected with COVID… that’s what happens.. you get hypoxic and then you die. Unfortunately these selfish people will kill many others doing their best to avoid COVID along the way.”

Gilman also alleged that his comments were being “taken out of context” by Republicans, then deleted the thread. He claimed, “I treat every patient that comes through the door with the same. Many gasping for breath and devastated when they find out covid is not a hoax.”

Gilman’s tweets have caused him trouble before. In December, he claimed he was professionally sidelined after alleging in a Nov. 22 Twitter post that there were “no more” intensive care unit (ICU) beds in the state, reported. Data from the Arizona Department of Health Services on the same day indicated only 10% — or approximately 175 total — of the state’s ICU beds were available, reported the AZ Mirror. The outlet also noted that some hospitals were reporting local inability to transfer patients to ICU care.

The Centers for Disease Control and Prevention’s COVID-19 data tracker reported that the United States had 26,277,125 cases and 445,264 deaths due to COVID-19.