We’ve all been there…you board your plane, headed somewhere nice and warm, so you’re dressed for where you’re landing. Probably in shorts and a T-shirt.
As you get all settled for your 3-hour flight, you notice it’s a little chilly inside the plane. But you figure it’s because the passenger door is still open, it’s cold outside, and air is blowing in from the jet bridge. It’ll warm up once you get on your way.
The plane takes off, and as you sit there, you realize it’s still pretty cold inside the plane. It never does warm up, and by the time you land in sunny, warm Pick A Place, you’re freezing.
Why is it so cold?
So what’s up with that? Why is it so cold on planes? It turns out there’s an actual, medically-based reason, far beyond the usual theories you might’ve heard.
ASTM International (formerly known as American Society for Testing and Materials) is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. Including planes. They conducted a study examining the correlation between people fainting in flight and the plane’s cabin pressure and temperature.
A medical reason
They discovered that the risk of people fainting (the medical term is “syncope” [SINK-oh-pee]) in-flight was about 3–9 per 1000 passenger flight hours, depending on the type of aircraft. They also realized this was happening because of a medical condition known as hypoxia. Hypoxia is when body tissues don’t receive enough oxygen, and ASTM International’s study determined that high cabin pressure and warm temperatures can both increase the chance of this reaction, even in otherwise healthy people.
Airlines can’t control cabin pressure the same way they can control temperature, but they can keep the cabin temperature on the cooler side to help reduce the risk of syncope.
At what temperature do they keep planes?
Despite the study and its findings, federal agencies don’t have specific guidelines for the temperature inside a plane cabin. However, the Association of Flight Attendants, the union representing 50,000 members working at more than 20 airlines, has been campaigning for years to get the federal government to put standards in place for cabin temperatures (The only temperature regulation now requires the cabin temperature to be within 5 degrees of the cockpit, but it doesn’t set minimums or maximums). They recommend a range of 65 to 75 degrees Fahrenheit.
Of course, the fact that you tend not to move around and just stay in one space just reinforces the feeling of being cold. If you were moving around the plane, you wouldn’t feel the chilliness as badly.
Oh, and if you could swear that planes used to be warmer years ago, you’d be right. The study was done in 2005 and published in 2008.
So if you tend to get chilly easily, bring a sweater with you on that plane. Just in case you need it.
Want to comment on this post? Great! Read this first to help ensure it gets approved.
Want to sponsor a post, write something for Your Mileage May Vary, or put ads on our site? Click here for more info.
Like this post? Please share it! We have plenty more just like it and would love it if you decided to hang around and sign up to get emailed notifications of when we post.
Whether you’ve read our articles before or this is the first time you’re stopping by, we’re really glad you’re here and hope you come back to visit again!
This post first appeared on Your Mileage May Vary
4 comments
Colder cabins are also helpful for people prone to motion sickness, as lower temps help with regulation of that.
Like I said, there are the “theories” that everyone has. Air sickness. Keeping people awake. Sadistic FAs ;-). But the main reason is syncope.
I call BS.
The airlines can control cabin pressure way better than they can control temperature. They can set it to exactly what they want it to be (up to the pressurization limits of the fuselage which is 8K’ cabin altitude) Cabin pressure is pretty uniform throughout the cabin, but temperature can vary a lot more. For instance, people in aisle seats experience a warmer temp than people in window seats. The window seats on the sunny side of the cabin are noticeably warmer than window seats on the shaded side. I do my best to sit on the sunny side of the cabin whenever possible (even if the window shade is closed) because IME it is warmer on that side. I expect that the FA set the cabin temperature to suit themselves. They tend to stay in the center of the cabin, are moving around, and have to wear whatever uniform the airline decrees. They do not get to dress for comfort.
People sitting, doing nothing much are at low risk for fainting (sinkope) even at lower cabin pressures regardless of the temperature.
re: “People sitting, doing nothing much are at low risk for fainting (sinkope) [sic] even at lower cabin pressures regardless of the temperature.”
Thank-you for your armchair diagnosis, Dr. Google. Now let’s see what the experts say: “A study of 11,920 in-flight medical emergencies found that syncope or presyncope accounted for 37.4 percent of cases. These calls were reported by five domestic and international airlines from January 1, 2008, through October 31, 2010. The medical profession’s page on Lufthansa’s website reports that the IATA Medical Advisory Group has recorded an increase in recent years of onboard medical incidents. Lufthansa has also noted an expected increase, with a current estimate of approximately one instance per 24 intercontinental flights.” Effective prevention: Keeping the cabin cool is a known preventive strategy. ASTM International studied the link between cabin pressure, temperature, and fainting and found that warm temperature contributes. Airlines decided to make their cabins chilly after take-off to curb the number of incidents.