I traveled to the United States from Frankfurt, Germany, in May. I've been on the same flight before, so I knew to be prepared with a sweater. Now, I'm sensitive to the cold, so this time I also brought along a thermometer. It was 51 degrees Fahrenheit (although sometimes it inched up to 53). Many of the passengers were wearing heavy jackets, and people were coughing. Why would they keep it so cold?
One possible answer: because they don't know it's that cold.
Remember that, as a passenger, you are in someone's workplace, and it's not yours.
Just as some restaurants tend to seem a little too cold, some aircraft cabins feel frosty because the people rushing to serve you are expending energy. You, on the other hand, are sitting there doing nothing but losing body heat and killing brain cells. So the flight attendants may not realize it's uncomfortable.
Further, you may be less comfortable because of your own anatomy. One theory holds that people who live in cold climes develop stocky bodies that retain heat and that people who live in warm climes are lean and lanky so they can throw off heat.
So if you're tall and skinny, you're going to feel the cold. If you're not used to cold weather - there really is something to the theory of acclimation - you're also going to feel it. Still, 51 degrees is so cold that you'd think that seeing little puffs of breath would tip somebody off that it's a tad chilly. Alas, the Federal Aviation Administration doesn't regulate cabin temperature. But the American Society of Heating, Refrigerating and Air-Conditioning Engineers has developed a standard that addresses air quality, including temperature, in airliners.
Among its many suggestions: It should never be colder than 65 or hotter than 80 (or 85, if the in-flight entertainment system is on).
Adoption of the standard, unveiled in May, could take several years if the FAA launches the rule-making process, said Byron Jones, associate dean of research at the College of Engineering at Kansas State University and chairman of the committee that developed the plan.
Until then, you're at the mercy of whoever is in charge of the thermostat - just like at home. Your best defense is dressing in layers and taking a silk sleep sack (akin to a sleeping-bag liner but in silk), which takes up little room and is easy to slip into.
If you're still cold, ask a flight attendant to warm it up. If you don't get any satisfaction, sitting there seething may, in fact, raise your body temperature. And that's some cold comfort.