Should Airlines Have Rules About Cabin Temperatures?

A common piece of advice for flyers is to bring a jacket in case it gets chilly on the plane. However, this wisdom only applies to flights that are already in the sky with the air conditioner on full blast. There's another period of time when flights can get quite hot: boarding.

In the typical boarding scenario, planes haven't yet engaged their climate control systems, so the temperature of the cabin is bottleneck version of the weather outside. The effect is like a car becoming uncomfortably hot if it's left sitting in the sun for too long with the windows rolled up.

As global warming causes temperatures to surge worldwide, many passengers are left sweating on overheated flights. Cabin temperatures on planes are simply too high.

A Problem Without Regulation

What's the ideal plane temperature? This question has never been officially answered by airlines or other regulating aviation bodies, so there are no standards to follow. The Federal Aviation Administration (FFA) only mandates that there's no more than a 5°F difference between the cockpit and cabin. It doesn't specify an acceptable temperature range, and there are no maximum temperature limits.

At least one organization has tried to change this. The Association of Flight Attendants (AFA) is an American-based group that's been drawing attention to overheated flights for years. Their first major attempt was in 2018 with a petition to the Secretary of the U.S. Department of Transportation to "conduct rulemaking to prevent incidents of extreme onboard temperature conditions on commercial airplane flights."

Cabin temperature standards, they argued, were a necessity for the safety and well-being of passengers as well as flight staff.

They weren't wrong. There have been multiple incidents of overheated flights causing emergency situations during boarding.

A History of Overheated Cabins

In the summer of 2023, a man on a Las Vegas flight had to receive emergency treatment after suffering from heat exhaustion. The plane wasn't even in the air yet; it was during an overly long boarding process. Delays had kept the aircraft on the tarmac for hours as outdoor temperatures rose to a blistering 115°F.

How hot was it inside of the cabin? No one had a thermometer handy, but according to the AFA, the heat was in the "triple digits." Delta would later release a statement acknowledging the "uncomfortable temperatures inside the cabin."

According to Sara Nelson, the president of the AFA, multiple people on the same flight had to be taken to the hospital for heat-related issues. The flight itself never took off; it was eventually cancelled after all of its delays.

Other dangerously hot planes have been recorded by the AFA as well. In the summer of 2017, a Denver flight made headlines after flight attendants had to call an ambulance for an overheated infant. One news outlet dubbed the plane "an oven with wings." Fortunately, the baby recovered.

When the AFA petitioned the government for cabin temperature regulations, it also created an app where passengers, crew members, and flight attendants could lodge complaints about overheated cabins. In five years, it's received more than 4,000 reports. 80% were about extreme temperatures during the boarding process alone.

The Science Behind Cabin Temperatures on Planes

There are a number of reasons for flights that are too hot.

The major one is called "in-flight crowding." Simply put, there are too many people on the plane, and it generates an excessive amount of heat. The heat is caused by everything from the kinetic energy of people's movement to the usage of electronics like in-flight entertainment screens.

How bad is overcrowding? The average flight has an occupancy of over 85%. During peak travel season, this number can reach 100%. If the airline has been overbooking itself to the point of kicking passengers off, it's more than 100%. That's a lot of heat being generated in a contained space.

Another issue is cost cutting by airlines. Technically speaking, planes can't turn on their air conditioners until they're airborne; their climate control systems are powered by their engines. However, there are auxiliary power units (APUs) that handle the onboard electrical systems during boarding and disembarking. They just eat up fuel, so pilots are under pressure to limit APU usage while planes are still at the gate.

Last but not least, some plane temperatures are reflecting a bigger and more global problem: climate change. As everyday weather becomes more extreme, it has a ripple effect on things like cabin comfort. An airplane from 20 years ago might've been able to sit in the sun for an hour or two without baking everyone inside. In today's temperatures, that just isn't possible.

Proposed Solutions for High Plane Temperatures

It might sound obvious: If cabin temperatures are too hot, make a rule that they need to stay cool.

The AFA proposes a standard cabin temperature of 80°F at all times, including boarding. They make an allowance for 85°F when in-flight entertainment is engaged and screens and other electronics are generating more heat.

The problem is that many airlines do have internal policies about cabin temperature. However, there's no federal regulation surrounding it. In other words, there are no consequences for breaking their own rules.

This is what happened with the man in Las Vegas who suffered from heat exhaustion. His airline, Delta, had regulations about cabin temperature that were "very similar" to the proposals sketched by the AFA. However, the cabin that day reached more than 100°F.

"This shows," said AFA president Nelson, "that without a federal requirement, [airline] policies are oftentimes set aside."

The Best Airlines for Cabin Temperatures

Are there any airlines with a better reputation than others for staying cool?

Sprint and Hawaiian have been recognized for their cabin temperature limits. Their flight attendants receive instructions to not let passengers board when interior temperatures exceed 85°F. American Airlines has the same policy with the limit of 90°F.

Other airlines either don't have or don't report their maximum allowed cabin temperatures. These brands include United, Alaska, and Frontier.

Adding to the issue is the fact that airlines function as their own authorities, leaving standards and practices to vary wildly throughout the industry. For example, some airlines track cabin temperature through their flight attendants: They'll distribute key chain thermometers that flight attendants carry for inspections. Other airlines will leave the decision up to different members of the flight crew.