Why planes are always pretty cold when you fly

Whether you're a frequent flyer or you jet of once in a while, tips and tricks to ensure you make the most of your flight are always welcome. For example, did you know that this is how to sleep on a plane and make sure you get a good snooze? Or that that this is the most popular plane seat (so book it if you can)? How about the fact that you should never drink water on a plane according to flight attendants?

And when it comes to the aircraft itself, there are a few questions we've already answered - like why you need to open your window blind during take off and landing, and why we show our boarding passes at the airport.

But if there's one thing that makes travelling that bit less comfortable is the temperature of the plane. Ever noticed how chilly it can be? Of course you have. Whether or not your neighbour has the aircon on full blast, jumpers and blankets are essential - especially on a long haul.

Why?

Apparently, there are a few reasons that you feel the chill when you fly.

A study by ASTM International reviewed why passengers faint during a flight. It found that a 'deficiency in the amount of oxygen reaching the tissues' is more likely to happen during a flight due to the cabin pressure. If the aircraft is too warm, it can also increase the likeliness of passengers passing out.

Secondly, in a report commissioned by the House of Lords, Airbus found that appropriate ventilation keeps the plane fresh, explaining: 'The heat given off by passengers in a fully occupied cabin is considerable. Incoming air needs to be at or below the required cabin temperature if that temperature is to be maintained.'

Lastly, flight attendant Monserrat Andujar-Geacoman added to Insider that planes are kept cool to 'accommodate emergency equipment and cockpit instruments.'

So now you know.