For the last several years, airline passengers have been asking themselves, “am I getting larger, or is my seat getting smaller.” It’s been no secret that the airlines have been shrinking the size of personal space on airplanes. After years of losing lots of money and flirting with bankruptcies, the airline companies have turned the corner and have become profitable again, thanks in large part to adding the number of seats on plane along with those little add-on fees like charging for baggage, or extra leg room.

In a wait, say that again moment, Southwest Airlines has announced they will begin to use larger seats in their 737-800s passenger jets beginning in mid-2016 and in the new 737 MAX in 2017. The seats are 0.7 inches wider than those currently used and offers more leg room. They also weigh less resulting in having to use less fuel.

While passengers may be grateful Southwest is expanding their space instead of shrinking it, their motivation may be more than just customer satisfaction. A consumer advisory group set up by the Department of Transportation is worried that shrinking space might be dangerous for passenger’s health and safety.

There is serious concern about the increased danger passengers won’t be able to evacuate fast enough in an emergency situation. One official on the committee ironically noted that the government sets standards for the condition of dogs who fly as cargo, but doesn’t have minimum space standards for us humans.

Another worry is passengers suffering from deep vein thrombosis during long flights which could lead to a blood clot forming. It was noted during a recent hearing that passengers who sit by the window have twice the risk of getting deep vein thrombosis than those sitting in the aisle seats.

So what happens if airlines are forced to add more space for their passengers? The likely scenario is passengers paying more in fares to cover the loss.