Air travel is a luxury many of us enjoy but one common gripe is how cold it can get while youre on the plane.

Even after putting on the sweatshirt you packed in your carry-on bag and turning off the air vent above you, the temperature on your plane may still feel chilly, especially once youre in the air. So why does this happen? There are a few reasons and some of them are actually intentional.

There is a science behind the cold cabin, and its [often] for your benefit, said Jay Robert , a senior international cabin crew member and creator of A Fly Guys Cabin Crew Lounge .

We talked to travel experts about how temperature is controlled throughout the aircraft, why the cabin often feels cooler once the plane is in flight, and tips for staying comfortable.

How is the temperature controlled on the airplane?

When your plane is at the gate, there is usually an external air conditioner, which you may have noticed as big yellow tubes connected to the plane, Robert said.

An auxiliary power unit, a small engine located in the tail of the aircraft, is also used to try to cool a hot cabin when the plane is on the ground. When youre in the air, most planes have a cooling system that works when the engine is on.

Generally, once youre in flight, pilots control the master thermostat, and then the crew in the cabin can move that up or down slightly using their cabin control system, Robert said, adding, If we need to make a significant change, we must call the pilots and ask them to do it.

While many airlines have set cabin temperature policies, there is currently no federal regulation for cabin temperature, according to Taylor Garland, spokesperson for the Association of Flight Attendants. The AFA submitted a petition in 2018 to the Department of Transportation for a cabin temperature standard. The DOT is still studying if standards should be set for cabin temperatures, according to The New York Times .