The tiny amount of time you have to put your oxygen mask on before passing out

When the flight attendant tells you to put on your own oxygen mask before helping others - you best listen - to avoid the risk of passing out yourself.

If the thought of a plane having to make an emergency landing wasn't scary enough, it turns out that you've only got a small amount of time to put on your oxygen mask before things start to become 'disoriented'.

And keeping your calm by putting your oxygen mask on first is rule number one.

Sergio Azenha / Alamy Stock Photo

We've all been there - the flight attendant is running through their safety demonstration in the middle of the plane and you're too 'busy' to listen.

Maybe you're already picturing the sandy beach, or how early you're going to wake up to secure a sunbed by the pool - either way - it's important you know how to put your mask on correctly.

However, learning how to put an oxygen mask is only half the battle, as you'll need to do it within 30 seconds.

"Once the cabin loses oxygen, passengers can become lightheaded and disoriented... and then lose consciousness," expert George Hobica told Huffington post.

"It's important to act quickly."

Finnbarr Webster / Alamy Stock Photo

What's even more strange is that there's actually no oxygen on the plane - so what's in the masks?

Well it just so happens that the masks aren't installed with oxygen, rather they are attached to an oxygen generating system.

This is what produces breathable oxygen via a chemical reaction.

Once you release the firing pin, by tugging on the mask, the chemicals in the generator start to burn.

This burning smell, not too dissimilar to turning on a new oven, means that the chemicals start release oxygen gas, which is then channeled to your nose through a pipe.

JG Photography / Alamy Stock Photo

Masks usually provide breathable oxygen for 12-20 minutes, depending on the size of the generator.

Don't worry too much though as it's not all doom and gloom.

Patrick Smith, a pilot and author of Cockpit Confidential, explained: “Crashes or fatalities from pressure problems are extremely uncommon, even with a fairly rapid decompression brought on by a hole or puncture.

“If cabin pressure falls below a certain threshold, the masks will deploy from the ceiling, exposing everybody to the so-called ‘rubber jungle’.

“Should you be confronted by this spectacle, strap your mask on and try to relax.

“The plane will be at a safe altitude shortly, and there are several minutes of backup oxygen for everybody.”