Now think of how a joint burns. There’s always some weed left, the “roach,” as it is called.

“Marijuana burns at a much, much lower temperature than a commercially made cigarette,” said Glass. “Because of that, the person is inhaling a certain amount of unburnt plant material.”

That irritates the lungs in the same manner as ragweed, birch and oak pollen does for those allergic to them, he said.

“So right off the bat there are those patients who would be increasingly susceptible to having a bronchospasm or cough because they have a more sensitive airway.”

And since a dry cough is a key sign of COVID-19, any cough caused by smoking a joint of weed could easily mimic that symptom, making diagnosis more difficult.

There’s another factor as well. Weed not only calms you down, but it messes with your ability to function, and that does you no favors if you find yourself having a medical emergency during a pandemic.

“You’re reducing anxiety, but that is still a change in your thinking, a change in the way you are handling facts, how you’re grasping situations,” Glass said.

“Now there’s a health care worker who is gowned, gloved, possibly in a hazmat suit trying to get through to you. These are people who are trying to decide if you should be going home, coming into the emergency room, or worst case scenario, that you need to be put on a ventilator,” he continued.