OAKLAND, Calif. — For more than two weeks now, the Oakland Fire Department has had a new approach if it needs to send someone inside a home.

Instead of all four firefighters from its rig, just one firefighter in latex gloves, a respirator mask and a surgical gown enters the residence.

It's just one of the many ways that firefighters nationwide are trying to best address the coronavirus pandemic.

Many firefighters' primary roles have shifted over the course of a generation from putting out blazes to becoming first medical responders. That has put them at the forefront of efforts to help people who may be sickened by the coronavirus.

It also means they're sensitive to the shortages of protective equipment that have strained hospitals across the U.S. To date, nearly 7,000 firefighters have self-reported as having been exposed to the virus, according to an ongoing survey conducted by the International Association of Fire Fighters, the nation's largest firefighters' union.

But only 15 percent of the union's departments have reported in, Doug Stern, the group's spokesman said — implying that there are more yet to come.

On April 3, OFD spokesman Michael Hunt emailed NBC News to say that the department had sustained its first confirmed case of COVID-19, and that this firefighter has been self-quarantining since March 15.

#youroaklandfirefighters want all to know that we are taking every precaution with #coronavirus

When you call for help we might show up looking a little bit like surgeons! (1 of 2) pic.twitter.com/pFc7ri7fX6 — Oakland Firefighters (@OaklandFFs) March 13, 2020

Many departments — as highlighted in recent letters sent by the union to federal leaders — remain concerned about shortages of protective equipment. There are even reports of shortages of CaviCide, an antiviral disinfectant that hospitals and firefighters commonly use.

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"If we continue at the current burn rate, we would be out of gowns within two weeks," said Lt. Thomas Ruiz, a spokesman for the Albuquerque, New Mexico, Fire Department.

These firefighters' experience echo the findings of a March 27 report issued by the United States Conference of Mayors, which found that 88.2 percent of the over 200 cities that responded to its survey said they do "not have an adequate supply of personal protective equipment (PPE) other than face masks."

"There's no playbook for this. Everybody is making it up on the fly," said Zac Unger, the president of Local 55, the Oakland firefighters' union, who also serves as a firefighter in the city's Montclair neighborhood. "We're all trying to protect our members as best we can."

NBC News spoke with nine fire departments across four Western states and found that all are altering the questions dispatchers ask before firefighters are dispatched to assess callers for possible coronavirus exposure. Once they get there, they're trying to remain physically as distant as possible.

And they're getting creative with finding new supplies. Some have accepted donations of hand sanitizer made by local distilleries. The Phoenix Fire Department has ordered 500 cases of rain ponchos — to use instead of gowns — in case its $4.2 million worth of recently ordered supplies don't arrive soon.

"We're looking at doing things we never thought we would be doing just to slow that burn rate down," said Capt. Rob McDade, a spokesman for the Phoenix Fire Department. "If we get our shipment, we're good, and if we don't, we're in trouble."

Fire departments say it appears that most people are heeding the warnings by public health officials to stay home, which has been reflected in a notable reduction in calls for service — firefighter-speak for calling 911 for a fire or a medical emergency. Chad Costa, a battalion chief for the Petaluma Fire Department, north of San Francisco, said that his agency had experienced a brief reduction in call volume but that it had since returned to normal.

Firefighters, along with medical experts, say that as more people stay home, the rate of infections is slowed, which hopefully mitigates their exposure to the virus.

"That's what's going to help firefighters the most," said Stern of the International Association of Fire Fighters, who was a firefighter in Cincinnati for more than 20 years. "If you do get sick, calling 911 isn't going to get you a test any quicker."

People who decide to call 911 and speak to a dispatcher will likely be asked a series of screening questions focused on recent international travel and whether they're already being treated for COVID-19, the disease caused by the coronavirus, among many others.

"There's a list of questions that didn't exist two months ago," said Andrew Freeborn, a spokesman for the Kern County Fire Department, north of Los Angeles.

Departments have strongly encouraged callers, if at all possible, to meet them curbside or at their doorsteps to minimize potential exposure.

Firefighters follow much more cautious policies about who goes in and with what gear: typically gowns, gloves and N95 masks.The Reno Fire Department in Nevada, for instance, now will send in only two of the typical four firefighters assigned to a given engine, and the two who go in will be the only ones with N95 respirators to conserve their stockpiles.

"In the past we've treated them as single use, but now we reuse them," Fire Chief David Cochran said. "But I don't want to put the men and women of my department at risk. You can find new masks, but to find new firefighters — that's a heavy hit."

For now, firefighters are doing their best to stem the tide.

"We're standing on the beach waiting for the wave to break, and we don't know how big it's going to be," said Unger, the Oakland firefighter.