Canceled events, emergency messages and mask-clad pedestrians harked back on Thursday to the frenzy of uncertainty in the early days of the coronavirus pandemic as the Baltimore metropolitan area fell under a “code red” air quality alert for the second consecutive day.

Federal, state and local government officials are advising the general public to stay indoors or mask up outside in response to plumes of smoke from Canadian wildfires that have wafted into the mid-Atlantic. The hazardous conditions are forcing the suspension of after-school activities, shuttering businesses and prompting scrambles for well-fitting masks and other protective equipment.

Among those feeling the effects of the burn Thursday was Charles Werrell, a 72-year-old veteran who lives in Park Heights. Werrell lives with chronic obstructive pulmonary disease and uses oxygen around the clock to alleviate his symptoms.

Werrell said he’s had more difficulty breathing and feels as if he’s in a room where people are smoking cigarettes.

“I’d be lying if I said I didn’t feel it,” he said. Werrell has increased his oxygen intake when leaving the house. He’s been wearing a mask outside, but not the recommended N95; he said he does not have any on hand.

Experts say most people won’t experience short-term health problems from the smoke-filled air, but those with heart and lung disease are at risk. So are sensitive groups including children, people with heart and lung disease, older adults, pregnant people and outdoor workers. The general public has been advised to avoid strenuous activity outside until the air quality alert lifts.

Several parents said they shared in Werrell’s anxiety about the air conditions.

“I have two small children that are premature, and I worry about them being outside and breathing this air,” added Toni Phillips while on her way to work on Eutaw Street.

With the Baltimore region entering the height of its tourism season and warm-weather period, visitors said they would try to make the most of the hazy conditions anyway.

“I walked outside this morning and was so glad I packed my masks,” said Angela-Rose Myers, who flew from Miami to Baltimore for the Black Feminist Future conference Wednesday night.

Staying at the Lord Baltimore Hotel downtown, she took a short walk this morning and felt ”labored” in her chest.

“It’s eerie right now ... plus, you can smell the burnt aftermath in the air,” Myers said. ”I want to enjoy Baltimore because it might get worse before it gets better. You never know.”

Others said it aggravated all-too-familiar feelings that have surfaced since the start of the public health crisis three years ago.

“I was nervous about coming here today, because, since I had COVID when I start coughing I can’t stop,” said Tess Wolf, who visited Baltimore Thursday with partner Pablo Charriz. “So I get more nervous about starting coughing.”

Baltimore Mayor Brandon Scott, during a Thursday morning news conference that announced the coming departure of the city’s police commissioner, urged those who can to stay indoors. The city’s concentration of people with disabilities and people experiencing homelessness makes it especially vulnerable to air pollution.

”I know no one wants to be hearing from me talking about wearing masks again,” he said. “But we should know now that I’m only going to do that when it’s in the best interest of people’s public health and safety.”

It appeared that many city residents were heeding the mayor’s call by mid-morning Thursday. Some city libraries, distributing free N95 masks, already had run out by about 11 a.m. A representative from the Mayor’s Office of Homeless Services said city-funded outreach teams have also begun distributing high-quality masks to people experiencing homelessness and shelter-based residents, who, at city-funded shelters, were given the option to stay inside and not be discharged for the day.

Institutions from the Maryland Zoo to the Maryland Jockey Club said Thursday that they would be canceling activities or closing early. And a spokesperson from the Baltimore Ravens said the team had moved a voluntary practice indoors for the day. The new Annapolis Blues FC soccer team postponed its Wednesday match due to the air quality.

The air quality notice also has affected area school districts, with most Baltimore-area systems — including Baltimore, Anne Arundel and Howard counties — suspending outdoor activities, field trips and after-school programming. A message from Baltimore City schools advised that schools without air conditioning would be given masks for the day. And a spokesperson from the Carroll County school district said individual schools would be left to determine if kids should stay indoors.

Air quality monitors specifically are measuring fine particulate matter, which can come from conditions such as dense plumes of smoke. An air quality message from the Maryland Department of Environment noted that long-term exposure to the elevated fine particles will likely keep much of the state in the “unhealthy, code red” range until an expected front Friday brings some reprieve.

hallie.miller@thebaltimorebanner.com

Baltimore Banner reporters Sarah True, Kristen Griffith, Jonas Shaffer, David Lance, Anish Vasudevan and Sunny Nagpaul contributed to this article.