In June 2017, a 4-month-old baby was rushed to the hospital suffering from heat-related symptoms after more than two hours aboard an increasingly hot United Airlines plane on the tarmac at Denver International Airport.
The child recovered, but the incident showed how sometimes extreme temperatures can overtake an aircraft on a hot summer day, creating a cabin environment that can run from uncomfortable to potentially unsafe.
“Today there are no (federal) temperature standards that exist. Oftentimes, in a list of safety requirements, this becomes the last priority,” said Sara Nelson, international president of the Association of Flight Attendants-CWA, which represents about 50,000 flight attendants working for 20 different airlines. “Even when airlines have their own internal policies about heating and cooling aircraft … there’s not going to be a full solution here until there’s a standard that everyone will have to meet.”
Starting this month, thousands of flight attendants at airlines around the country will carry thermometers to document extreme temperatures, whether hot or cold, encountered during their shifts.
The data collected will be used to further bolster the push by two of the industry’s largest flight attendant unions to get the federal government to establish standards in cabin temperatures, with a recommended range of 65 to 75 degrees Fahrenheit.
Such rules could make temperature checks part of the standard preflight checklist, with passengers prevented from boarding planes unless the proper conditions are met.
Last week, the AFA and Transport Workers Union Local 556, which represents Southwest flight attendants, announced a smartphone app that flight crews and passengers can use to document extreme temperatures.
“It leads to fatigue for flight attendants. … It can create incredible discomfort for customers,” said Lyn Montgomery, president of the Southwest flight attendants’ union.
Airlines have a number of tools to keep aircraft cool while on the ground, including auxiliary power units that drive the plane’s air conditioning systems and the use of preconditioned air pumped onto the plane. Passengers are also often advised to put down their shades and open their air vents when exiting a plane to help keep things cool.
American Airlines said it won’t board an aircraft if the cabin temperature is above 90 degrees, and while Southwest doesn’t have a set limit, a spokesman said employees are empowered to decide whether the temperature is acceptable for boarding.
Montgomery, who represents Southwest flight attendants, said the carrier has a process to report high cabin temperatures, but flight crews still sometimes resort to wearing cooling scarves or plugging portable fans into their smartphones.
In an industry that includes major carriers as well as smaller regional operations and charter airlines, the attention paid to cabin temperature can vary widely, said Nelson, whose group represents flight attendants at United, Alaska, Frontier and three of American Airlines’ regional subsidiaries.
It doesn’t take long for a plane, especially smaller models, to heat up on the hottest of days, Nelson said, and the typical process can break down for any number of reasons: equipment might malfunction, the proper staff aren’t in place, or the plane has simply been sitting exposed to the sun for several hours before re-entering service after a maintenance-hangar visit.
With crews juggling a number of responsibilities, including needing to get the plane out on time, the temperature of the cabin might not be a top concern, she said.
The AFA filed a petition with the Department of Transportation in July recommending the target temperature range be set at 65 to 75 degrees Fahrenheit, with a maximum allowed temperature of 80 degrees. On aircraft with heat-generating seatback entertainment systems, the recommended maximum would be 85 degrees.
The temperature range recommended by the union is based on work done in 2007 by the American Society of Heating, Refrigerating and Air Conditioning Engineers that involved aircraft manufacturers, airlines and crewmember and passenger groups.
“This was an industry consensus, but they have not been put into regulation,” Nelson said. “Without those standards and requirement, it gets prioritized last or is not considered.”