As the government shutdown enters its third week, air traffic controllers are bracing for financial uncertainty: potentially weeks of work without a paycheck.

Deemed essential workers, air traffic controllers are expected to work during the government shutdown that began Oct. 1, but are not being compensated during the funding lapse. They received a partial paycheck on Oct. 14 for work performed before the shutdown, but will receive a $0 paycheck for their work over the next two weeks.

Nick Daniels, president of the National Air Traffic Controllers Association (NATCA), told Fortune the lack of compensation has heaped financial pressures on workers, who are already working six days a week for a total of 60 hours.

“To think that somehow we can live with, ‘You’ll get paid eventually,’ that doesn’t pay the creditors, that doesn’t pay the mortgage, that doesn’t pay gas, that doesn’t pay the food bill,” Daniels said. “No one takes IOUs, and the air traffic controllers are having to feel that pressure as well.”

Prior to the shutdown, air traffic controllers were already among the most stressed workers in the U.S., with the aviation industry suffering a shortage of controllers for more than a decade, exacerbated by scant funding for training, which has fallen behind the Federal Aviation Administration’s schedule. Before the shortage, 91% of U.S. air traffic control centers operated below the FAA’s recommended staffing levels, and the government shutdown has made the problem worse: Transportation Secretary Sean Duffy said earlier this month that air traffic staffing has been cut by 50% in some areas, in part as a result of controllers calling in sick.

How are controllers making ends meet?

The NATCA union, which represents more than 20,000 aviation safety workers, is looking into financial institutions providing no-interest loans. Some of the new workers just graduating from the FAA Academy in Oklahoma City and being placed in new positions have been required to move cross-country without a guaranteed paycheck, Daniels said. Longtime controllers have stepped in to provide meals and support for them.

Daniels noted other controllers are turning to “gig jobs” like driving for Uber or DoorDash, as well as becoming restaurant servers—positions that can accommodate day jobs or irregular schedules.

“It’s a world where they are now not only leaning on each other, they’re leaning on getting other jobs, going to their primary job in the day, and then in the evening, going out and having to do some level of a secondary job,” Daniels said.

Workers have also been receiving free food from airline flight crews, including from Alaska Airlines pilots who delivered pizzas to controllers at the San Francisco International Airport. Beyond U.S. pilots and flight attendants providing food for controllers, Canadian and Australian air traffic controllers have also stepped in to provide support, according to Daniels. Some of the larger airports are receiving food for controllers sometimes once or twice a day.

What is the impact of the shutdown on air travel?

Keeping morale up during the shutdown helps alleviate “that stress, that pressure, creating that fatigue, the unnecessary risk that it’s bringing into the system,” Daniels said.

During the 2019 government shutdown, air traffic controllers organized “sick outs,” refusing to work without pay. Further staffing issues would not compromise the safety of flying, but increased stress could lead more controllers to miss shifts, thus causing more flight cancellations. FlightAware reported more than 7,850 delays in U.S. airports on Sunday, as well as 117 cancellations. Duffy said 53% of the 23,000 flight delays over the course of a week earlier this month were the result of staffing issues. Usually, staffing challenges account for only 5% of delays.

White House spokesperson Kush Desai reiterated that the decision to end the shutdown rests on Democrats.

“Democrats could put an end to this disaster today by voting for the same clean funding bill that they voted for 13 times under Joe Biden—instead, they’re making everyday Americans pay for their stupid games,” he told Fortune in a statement.

Airports, including New York’s John F. Kennedy International Airport and Newark Liberty International Airport in New Jersey, have urged patience among passengers and refused to play messages by Homeland Security Secretary Kristi Noem blaming the shutdown on Democrats, saying the video violated airport policies on displaying partisan content.

Daniels insisted the impact of the shutdown on air traffic controllers was not just insular and would continue to impact the aviation sector and broader American economy.

“Controllers are not responsible for shutting and starting to shut down … The only people that can do that are the elected officials,” Daniels said. “That’s why the American people—we’re asking them to continue to stand up and say, ‘End this shutdown now.’ There is no scenario where we just have a game plan for no one having any money and continuing to work.”

Air traffic controllers are becoming Uber drivers and restaurant servers on top of six-day airport shifts to make ends meet during government shutdown