Updated

It’s just like your mom said: Always bring a sweater.

Every time you fly, you must fight the never-ending battle of temperature regulation. Especially for those coming from warm climates, it can seem impossible to get comfy when you’re hurdling through the air in a freezing tin can.

It turns out, there might be a medical reason why airplanes are kept so bone-chillingly cold.

According to a study conducted by the American Society for Testing and Materials, as reported by Business Insider, passengers are more likely to faint on board an aircraft versus on the ground. This is generally due to hypoxia, a medical condition that occurs when the body tissue does not receive enough oxygen — and it can happen a lot more than you think in plane passengers.

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Another thing that can trigger hypoxia is an overheated cabin, so that’s why temperatures are kept below average. While people can experience their environments differently, airlines can’t really adapt for everyone’s internal temperature specifications, so they regulate based on the average population and keep the cabin just a little on the cold side.

Retired Delta captain Paul Eschenfelder told Business Insider that newer aircraft are able to regulate cabin temperature more precisely because they have more advanced thermostats that allow temperature to be adjusted by row.

So, hopefully in the near future, there'll be no more messing with the air nozzle or asking for an extra blanket.