WHAT HAPPENS WHEN...

While the A-listers disembark looking rested, we steerage folk arrive in arrivals looking tested. So what really goes down when you’re at 38,000 feet?

...you fly long haul?

1UNDER PRESSURE

It’s a good thing the engine is so loud – because there is a lot of farting going on. ‘The altitude and lower-thanaverage air pressure in the cabin causes gas to expand, so you might experience abdominal bloating, discomfort and flatulence,’ explains Dr Gareth Corbett, consultant gastroenterologist at Cambridge University Hospitals. ‘And as your blood will only be at 92-94% oxygenation (a normal range is 95-100%), you’ll struggle to move food from your stomach to your small intestine.’

Lay off fizzy drinks and high-fibre or fermented foods and opt for still water or juice and white carbs, which will be more easily broken down by your stomach enzymes.

2FIRST-CLASS COMPLEXION

It’s not just your stomach that finds it hard to adjust. ‘Low humidity in the cabin over long journeys leads to a decrease in hydration in the outer layer of your skin,’ warns consultant dermatologist Dr Justine Kluk. ‘This may manifest in tight, peeling skin, dry eyes or chapped lips.’ To swerve sandpapery skin, navigate the tiny toilet cubicle to remove your make-up and apply a hyaluronic acid-based serum. It holds up to 1,000 times its weight in water molecules, drawing moisture deeper into the skin.

3RHYTHM AND BLUES

‘Your body clock runs in a circadian rhythm, meaning that it resets every 24 hours,’ explains Dr Christopher-james Harvey, associate director at Nuffield Department of Clinical Neurosciences. ‘It keeps your physiology ticking over and responds to cues like light, food and temperature.’ The upshot? Spend 12 hours in a tin can and your body clock loses its shit in the form of fluctuating cortisol and melatonin levels. Your sleep isn’t the only thing that suffers – it can also affect your concentration, coordination and emotions.

4MILE CRY CLUB

Speaking of emotions, if you’re weeping into your wet wipe, it’s no surprise. While there have been no peer-reviewed studies on why we cry on planes, researchers suspect that it could be due to some combination of sleep deprivation and hormonal upheaval as well as a phenomenon called ‘stranger intimacy’ – the strange combo of extreme proximity and cocoon-like comfort could be enough to set you off. Do yourself a favour – don’t watch

The Notebook, yeah?

5CABIN FEVER

Shooting wary glances at the serial sneezer in 14A? We don’t blame you. But while you can catch a cold on a plane, you’re no more likely to than you are at any other crowded indoor place, like the cinema. Save your scepticism for the tray table, which can harbour up to 10 times more bacteria than the plane toilet flush (ick) – and be sure to pack some antibacterial gel in your hand luggage.