JOHN YANG: As wildfires become more frequent and more devastating.

Wildland firefighters are often the last line of defense, protecting homes and communities, while these crucial public servants are in high demand right now, their paychecks are sometimes smaller than some fast food workers, and unless Congress acts, a temporary pay raise for federal firefighters will expire at the end of September.

Stephanie Sy has the story.

STEPHANIE SY (voice-over): This year's wildfires have already burned 5.4 million acres in the United States and forced thousands of people to evacuate their communities.

SUSAN SINGLETON, Wildfire Evacuee: People that we know that went by and looked at the property, said it's burned down.

Everything our stuff is all burned up.

STEPHANIE SY (voice-over): While fire evacuees flee to avoid danger.

Every year, thousands of wildland firefighters are deployed to the front lines.

LUKE MAYFIELD, President, Grassroots Wildland Firefighters: There's crews right now in the country that have already completed 7/14-day assignments, and on average, any more federal wildland firefighters are sleeping in the dirt and on assignment in excess of 130 days a year.

STEPHANIE SY (voice-over): Luke Mayfield was on a Hot Shot Crew for 18 years.

Hot Shot firefighters are called on to suppress the largest and most intense wildfires in the country, the mobile teams face grueling hours in tough conditions, and they're stretched thin.

In recent years, agencies have been short staffed by mid-July, even though the Forest Service had met its hiring goal of onboarding more than 11,000 firefighters.

Those numbers don't tell the whole story.

LUKE MAYFIELD: Across the nation, we are missing 25 percent of the desired capacity of, you know, roughly 18,000 federal wildland firefighters across the Department of Interior and United States Forest Service.

And if you look at geographically specific locations, especially in the state of California, some of those vacancy rates can exceed 50 plus percent.

STEPHANIE SY: These are very serious shortfalls you seem to be describing.

I don't think the average person understands.

Does that mean it's difficult to for containment?

Does that mean lives are threatened, homes are threatened?

LUKE MAYFIELD: All of the above.

There's not enough people to respond in a timely and adequate manner.

There's not enough people around, and that results in, you know, national level discussions of how you triage, where people go, and how many people are allocated to any given assignment on any given day.

STEPHANIE SY: Triage always means that there's a patient that suffers, and in the wildfire case, I guess that means there's something that burns.

LUKE MAYFIELD: Something that burns communities that are threatened, and it also means that mitigation and management work is not being done because everybody is responding to wildland fires.

STEPHANIE SY (voice-over): Wildfires this year in Ruidoso, New Mexico and Northern California have consumed hundreds of homes.

Firefighters themselves have suffered losses.

DAVE TEHAN, Volunteer Firefighter: I feel luckier than some of the people here, because we do have a few things, not very much, but a few things to hold in our hands that survived.

STEPHANIE SY (voice-over): With climate change increasing the severity and frequency of wildfires, trained wildland firefighters are needed more than ever.

But Mayfield, now head of a nonprofit that advocates for federal fire personnel, says the pay scale doesn't reflect the demands of today.

LUKE MAYFIELD: You need as much time on the fire line as possible in order to make a livable and planable income, which results in the regular need of trying to accrue a 1,000 or more hours of overtime.

For a majority of wildland firefighters.

STEPHANIE SY: You need to do 1,000 hours of overtime every fire season in order to make ends meet.

LUKE MAYFIELD: Yeah, I would say that is very fair to say, and that's 1000 hours and roughly a five to six-month period.

STEPHANIE SY (voice-over): Under the bipartisan infrastructure law, wildland firefighters were guaranteed a minimum wage of $15 an hour, but that expires this fall.

Mayfield and others are pushing Congress to pass legislation that would lead to a more permanent pay increase.

JOAN MOONEY, U.S. Department of the Interior: Everyone is looking for certainty, and we need that stable, sustained funding over time without congressional action and only reinforces the fears that wildland firefighters currently have about support, our support and our commitment to their careers that are needed.

ALEX ROBERTSON, National Fire Director, U.S. Forest Service: We have 30,000 firefighters in the system that are engaged on large fires.

We're seeing a lot of injuries.

We're seeing a lot of near misses.

We've had a number of fatalities.

STEPHANIE SY (voice-over): Alex Robertson is another former Hot Shot.

He still works for the Forest Service, but says the life of a wildland firefighter no longer fits his lifestyle.

ALEX ROBERTSON: I was married and had two young sons, and being on a hotshot crew, being away from home for that amount of time, being in a very dangerous line of work, wasn't going to play out very well.

STEPHANIE SY (voice-over): It also didn't play out well for Luke Mayfield, while he was helping save lives, he felt helpless in his own.

LUKE MAYFIELD: The only place that I ended up feeling normal was when I was on fires, and the only place that I didn't want to be was on fires, which for me, resulted in never diagnosed, but seasonal depression and a consistent conversation of whether or not my family was better off with a life insurance check versus me being at home.

STEPHANIE SY (voice-over): Better pay would have helped, but so would a more humane pace, says Robertson.

ALEX ROBERTSON: We know that our folks can't just go for the next two months, day in and day out at the pace that they're going right now.

It really is about building in some breaks, building in some rest, and so they can be effective and at their best at the end of the fire season, like they are at the beginning of the fire season.

STEPHANIE SY (voice-over): Despite the challenges.

Mayfield says wildland firefighters love what they do.

STEPHANIE SY: It sounds like the kind of job you would only want to do, single and young and for a couple of years, and yet you did it for 20 years.

What continued to drive you in this job?

LUKE MAYFIELD: I mean, it's a public service.

I think people are drawn to that, and it is the most gratifying and life shaping job that I've ever had.

It's the one thing that I did in my life that was truly motivating and motivated me to be a better person, be a better leader, and take care of people.

STEPHANIE SY (voice-over): Now they're asking lawmakers to take care of them.

For PBS News Weekend, I'm Stephanie Sy.