A dozen firefighters and emergency medical technicians in Maryland are under quarantine after authorities learned they had been inside a home in Prince George’s County occupied by a man who tested positive for the coronavirus.

Tiffany D. Green, chief of the county’s fire and emergency medical services, said one firefighter has shown flu-like symptoms that include a fever and is being tested for the virus. The others, all self-quarantined in their homes, will be tested if they become ill.

“We’re following our normal infectious disease procedures,” Green said, adding that firefighters have been trained on how to monitor themselves for symptoms of covid-19, the disease caused by the virus, and will notify county officials if they show signs of the illness.

Authorities in the area and across the country are starting to grapple with how first responders deal with the fast-spreading contagion, as they respond to calls for crime and medical help while trying to keep themselves safe and minimize exposing their colleagues and families.

Daniel Linskey, a former superintendent in chief of the Boston Police Department and now a security consultant, said law enforcement agencies should even consider how they respond to calls that are not emergencies.

“Do we need to roll police to homes to take a burglary report,” Linskey said, “or can it just be taken over the phone?”

In addition to the scare in Prince George’s County, two D.C. firefighters have self-quarantined after responding to an incident, according to the head of the firefighters union. District officials did not respond to questions seeking further details.

D.C. Police Chief Peter Newsham said his officers have been trained in dealing with the virus, and many carry protective clothing because they often interact with people at risk for hepatitis, influenza and other infectious diseases. He said officers who come in contact with someone showing signs of the virus can ask them if they will put on a mask, and if they refuse, the officers will put one on themselves.

“The key for us is to ensure our officers have sufficient information about how the virus is transmitted to ensure they don’t come in contact with it,” Newsham said. “Anyone who exhibits symptoms, we ask them to stay home.”

The chief said the department is evaluating on a case-by-case basis events it hosts that attract groups or invite close contact, such as the popular coffee with a cop events. He said roll call rooms, where officers are briefed in stations before their shifts, are cleaned after every meeting.

Court officials across the region also are taking steps to limit the number of people entering the normally busy courthouses.

Federal court officials in Washington on Thursday announced restricted access to the U.S. District Court and the U.S. Court of Appeals for the D.C. Circuit. Under the new guidelines, only judges, court staff, reporters and people with “official business with the courts” would be allowed to enter the courthouse. People delivering court filings must use drop boxes instead of entering the court clerk’s office.

The Maryland judiciary announced it would be suspending jury trials starting Monday through April 3, “given recommendations from public health authorities to limit large gatherings.” In D.C. Superior Court, employees who monitor defendants under court supervision may be permitted to monitor hearings by telephone, city officials said.

And the Eastern District of Virginia, which includes federal courthouses in Alexandria, Richmond, Norfolk and Newport News, is postponing all hearings for misdemeanor, traffic and petty offenses that are scheduled between March 16 and April 30.

Arlington County’s police department has ordered additional protective gear “as a precaution,” spokeswoman Ashley Savage said, and canceled an anti-drunken-driving event scheduled for this weekend.

Fairfax County police said officers are following guidance issued by the Centers for Disease Control and Prevention for frequent hand-washing, carrying protective gear like rubber gloves and disinfecting uniforms after close contact during an apprehension.

The issues in the D.C. region illustrate the dangers and complexities faced by first responders and other public safety entities.

The dozen firefighters and EMTs in Prince George’s County now under self-quarantine had at one time or another been in the infected man’s home during three separate visits by emergency personnel over the course of a month. It was unclear how many had direct contact with the man, described only as in his 60s.

The county’s chief health officer, Ernest L. Carter, said there is no evidence the man, Prince George’s fourth confirmed coronavirus patient, had traveled. “It seems like this was community-acquired,” Carter said.

Stephen Bigelow Jr., the chairman of the union that represents D.C. police officers, said efforts by government officials and others to cancel large-scale events are helpful to officers who often are assigned or volunteer to work security and crowd control.

But he said preventing the coronavirus among first responders who must work in the community will be difficult. “Honestly, I don’t know how you prevent it from spreading, short of wearing masks everywhere you go,” he said.

On Wednesday in Montgomery County, operators at the 911 center began asking all callers a standard question,

according to Assistant Fire Chief Alan Butsch of the county’s Fire and Rescue Service: “For responder safety, does anyone involved or at that location have a cough or fever?”

“If they answer in the affirmative, our crews are going in with masks on,” said Butsch, who heads up the department’s emergency medical services section.

Dabney Hudson, president of the union representing D.C. firefighters, said dispatchers at the Office of Unified Communications, the 911 center, are trying to screen calls to isolate potential virus patients, so firefighters and paramedics can prepare before arriving at a call.

Hudson said only two firefighters or paramedics will assess a patient who either fears having the coronavirus or exhibits symptoms, instead of an entire crew of four or six people. If there is a real concern, they wear protective gear that includes masks, gloves and face shields.

At many hospitals in the District, Hudson said patients who are suspected of having the virus are triaged inside the ambulance, parked away from the emergency room entrance. Then the ambulance has to be removed from the street and disinfected.

“We’re trying to work through it,” Hudson said. “We make sure we have access to protective equipment, such as masks. But I don’t think we’re ever going to have enough masks to go around. It’s not feasible when we have a thousand calls a day.”

Ann E. Marimow, Justin Jouvenal, Keith L. Alexander, Dan Morse and Rachel Weiner contributed to this report.