As if a major snowstorm followed immediately by a polar vortex wasn't enough for airlines to handle, newly imposed regulations from the Federal Aviation Administration (FAA) added yet another challenge.
The new rules require pilots to have a minimum of 30 consecutive hours free from duty each week and 10 hours of rest, including the opportunity for eight uninterrupted hours of sleep, before each flight duty period. Airlines have had two years to prepare for this rule change, but the timing still isn't ideal.
See also: 13 Photos That Prove Cold Weather Makes People Crazy
Airlines have canceled more than 15,000 flights since Friday and delayed tens of thousands more, according to FlightAware.com. While the weather has made several aspects of flying more challenging, the FAA implemented a long-expected overhaul of the rules this weekend to protect against pilot fatigue.
"It’s rather unfortunate that the day the new rule change became mandatory happens to coincide with this massive weather system," Capt. Sean Cassidy, the vice president of the Air Line Pilots Association, told the New York Times.
It's difficult to determine the exact role of the new FAA rules in the recent glut of canceled and delayed flights, but JetBlue, which canceled about 300 flights during a 17-hour period ending on Tuesday at 10 a.m. ET, admitted in a statement that "newly launched FAA regulations on pilot duty times caused delayed flights to quickly turn into canceled ones."
The so-called polar vortex has brought "dangerous, and in some cases life-threatening, low temperatures and wind chills," according to the National Weather Service. The NWS reports wind chill values dipped below -50 degrees in parts of the country early Tuesday, some of the coldest temperatures in 20 years.
Exposure to such extreme weather puts people at risk for hypothermia and frostbite. At least one airline, United, has implemented a 15-minute limit for how long ground workers and baggage handlers can stay on the tarmac at a time. The following NWS chart shows approximately how long it takes for frostbite to set in at various wind chill temperatures:

The weather isn't just affecting air travel. About 500 Amtrak passengers were stranded overnight Monday, when a 12-foot snow drift impeded three trains 80 miles outside of Chicago.
Have something to add to this story? Share it in the comments.
Image: Justin Sullivan/Getty Images