Traveling during the holidays is always stressful, and there’s a chance it might get even more stressful this year thanks to the longest government shutdown in U.S. history.

On Wednesday, U.S. Transportation Secretary Sean Duffy announced he is ordering a 10 percent cut in flights at 40 U.S. airports, Reuters reported in an exclusive. Why? The U.S. government is on the 36th day of its longest shutdown in history (the previous record was set by the first Trump administration). As a result, there are concerns about air traffic control safety as 13,000 air traffic controllers and 50,000 Transportation Security Administration agents work without pay, according to Reuters. The timing couldn’t be worse for people planning to visit family or friends over the fall and winter holidays.

Republicans blame Democrats for the shutdown. Democrats blame Republicans for the shutdown. Meanwhile, thousands of federal workers are without paychecks.

“We had a gut check of what is our job,” Duffy told reporters, according to Reuters. “Our job is to make sure we make the hard decisions to continue to keep the airspace safe.”

The FAA added that international flights are excempt from the reduction cuts.

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“When we see pressures building in these 40 markets, we just can’t ignore it,” FAA Administrator Bryan Bedford said at a press conference, Reuters reported. “We can take action today to prevent things from deteriorating so the system is extremely safe today, will be extremely safe tomorrow.”

According to CNBC, the flight cancellations are a “proactive” measure, Duffy said. The reduction goes into effect on Friday, NBC reported.

What to do online if you’re flight is canceledBefore you head to the airport, make sure your flight is still on. You can do that by heading to the airports website or your airline’s website. If it is cancelled, check with your airline to see if you’re owed a refund or other types of compensation, and then figure out your next move. Can you take a train to your destination, or rent a car? Is there another airline you can switch to?

If your travel plans get mixed up this year, you can figure out a lot of the mess from the comfort of your home — as long as you check online before you leave.

FAA flight reductions: Full list of 40 airports reportedly threatened by shutdownDuffy did not say which 40 airports would be affected, but said that the airports experience “high volume,” meaning it’s likely an airport you’re traveling through. No official list has been released by the FAA, but reports from ABC News and CBS News, citing anonymous sources show that these are likely the affected airports. The FAA did not immediately respond to a request from Mashable.

Anchorage International

Baltimore/Washington International

Boston Logan International

Charlotte Douglas International

Chicago Midway

Chicago O`Hare International

Cincinnati/Northern Kentucky International

Dallas Love

Dallas/Fort Worth International

Denver International

Detroit Metropolitan Wayne County

Fort Lauderdale/Hollywood International

George Bush Houston Intercontinental

Hartsfield-Jackson Atlanta International

Honolulu International

Houston Hobby

Indianapolis International

Las Vegas Harry Reid International

Los Angeles International

Louisville International

Memphis International

Miami International

Minneapolis/St. Paul International

Newark Liberty International

New York John F. Kennedy International

New York LaGuardia

Oakland International

Ontario International

Orlando International

Philadelphia International

Phoenix Sky Harbor International

Portland International

Ronald Reagan Washington National

Salt Lake City International

San Diego International

San Francisco International

Seattle/Tacoma International

Tampa International

Teterboro

Washington Dulles International

We’re not going to say the Trump administration is threatening to hold Thanksgiving hostage in the shutdown fight. There are legitimate worries about air traffic control staffing. But we’re not not saying that.