Why my in-flight air nozzle always stays on

Even if you're freezing, travel experts say you should never turn your air nozzle off during a flight. Here's why. 

Allow me to vent...

You toss and turn. You clutch a blanket. A jet of cold air tickles your forehead. You shiver and think: "Just 8 hours to go."

No, you're not bivouacking Everest: you're on a long haul flight.

Sound familiar? Of course. We've all been here, and we've all been tempted to turn off the air vents above our head, to (mildly) increase our chances of survival in such a freezing cold environment. 

But maybe you shouldn't touch them. Why? According to Dr Mark Gendreau, chief medical officer at Beth Israel Lahey Health, Beverly Hospital, having them on could reduce your chances of getting sick.

Dr Gendreau claims your air vent may help disperse the tiny percentage of germs your aeroplane's central HEPA filters (the same devices used in hospital operating theatres, which remove 99.97 of dust, pollen, mold, bacteria, and any airborne particles that go through them) may fail to clear.

"A lot of people don't take advantage of it, but... it... provides you with a little more air turbulence in your area that you're sitting in," Dr Gendreau told The Daily Mail. 

"If there is a viral particle coming your way, theoretically it can push that and move it quickly out of your space."

Before you fear doing this will make you hypothermic, don't worry. Dr Gendreau added: "It doesn't need to be pointed at you. It just needs to be pointed a little bit in front of you and down."

Consider me sold (and wrapped in a thick wooly jumper). 

Though I hate being cold, I will always keep my air gasper (gently) on during a flight.

That said, it is also worth noting that aeroplane cabin air (regardless of whether you turn on your air gasper nozzle) is some of the lowest in particulates (in public indoor spaces) around.

One study even suggested it could be cleaner than your office's (according to the IATA, cabin air is refreshed 20-30 times an hour, which is about 10 times more than most office buildings).

Some research has also suggested that turning your air gasper on may not have any significant impact on the transmission of illness, with the important lifting (or in this case, air filtering) already having been done by the central air conditioning.

If there's any chance of it reducing my chances of getting sick though, you can be sure I'll be packing warm clothes and whacking it on.

Originally published as Why my in-flight air nozzle always stays on