Right after boarding, many feel a shiver run down their spine – the cool breeze flowing through the cabin. Especially when it's summer heat outside, the climate on board often feels like a time travel towards winter. But why does the crew intentionally set the temperature so low? Behind the chill lies a solid reason, which primarily serves the health of the passengers.

Cool air above the clouds

Upon entering a passenger airplane, one thing is immediately noticeable: it is significantly cooler than at the gate. Many travelers quickly reach for their jackets or ask the cabin crew for an extra blanket. Complaints about the cold tend to increase, especially on long-haul flights. Studies show that temperatures usually range between 20 and 24 degrees Celsius – cooler than in many living rooms. However, this is not a coincidence but a calculated safety mechanism.

Airplanes operate at extreme altitudes - cruise flights take place at 10,000 to 12,000 meters above regions with outside temperatures of up to -60 degrees Celsius. To ensure a comfortable and safe environment on board, the cabin air is treated, filtered, and conditioned. Not only temperature plays a role, but also air pressure and oxygen saturation. This creates an environment that may feel cool to many, but ultimately feels safe.

Medical reasons for cool temperatures

Why then risk passengers freezing instead of ensuring a comfortable warmth? The answer can be found in medical research. On flights, there is an increased risk of so-called syncopes – short-term fainting spells. Even under normal pressure conditions and with low oxygen saturation, people in the air are more susceptible to circulation problems than on the ground.

If it gets too warm in the cabin, the risk increases further: the blood vessels expand, blood pressure drops, and the body receives even less oxygen. Studies from the USA confirm that the risk of loss of consciousness significantly increases in overly warm airplane cabins. The relatively cool temperatures help stabilize circulation and reduce the risk of such incidents. To prevent this from becoming a health risk, airlines rely on empirical data and medical recommendations.

Balance between comfort and safety

The setting of the temperature is not an exact science, but rather falls within a range that offers a compromise between comfort and safety. <strong>Lufthansa</strong>, for example, typically sets the cabin temperature between 20 and 24 degrees, with smaller adjustments made by the flight attendants themselves – larger temperature changes must be approved from the cockpit.

Despite all the standardization, there are no fixed international limits for the temperature on board. Instead, the crew responds to the needs of the majority of their guests and reacts flexibly to complaints. As a result, multiple climate zones are sometimes created within an aircraft to ensure the satisfaction of as many people as possible.

"Cool temperatures protect against circulatory problems. Therefore, the temperature on board is kept rather low. The crew ensures a comfortable room temperature for the passengers," explains a spokesperson for Lufthansa.

Other major airlines also follow this philosophy. Investigations by the German aviation authority and the international airline association IATA confirm that the prevention of circulatory problems is the main reason for the intentionally cool cabin temperatures. There are additional factors: less heat also means less ideal conditions for bacteria and germs, which in turn benefits overall health on board.

Outlook: Will the climate on board remain frosty?

It seems that thick sweaters and light blankets will continue to be the best companions for air travel in the future. Since safety and medical health are the top priority, airlines will likely continue to resist the demand for significantly warmer cabin air. However, modern aircraft and intelligent air conditioning systems could allow for more flexible temperature zones in the coming years, enabling individual preferences to be taken into greater account. Until then, shivering above the clouds remains the lesser evil.

Further information is provided by health organizations such as the World Health Organization (WHO) or aviation associations with up-to-date recommendations for well-being while flying.