Why you probably shouldn't answer that important email while flying

According to Professor David Gradwell from Kings College, travelling by plane can make it more difficult to think as change in air pressure means brain has less oxygen that diminishes performance.

Revealing a series of "don'ts" for would-be travellers, he said that aircraft cabins are pressurised but only to a level equivalent to that on top of a 6,000 to 8,000 feet mountain where the air is thinner and less oxygen reaches the brain.

In case technology improves to make Internet access more popular while flying, "it may not be the best place to answer that important email," he advised.

He added passengers should not fly east if they want to avoid jet lag, 'The Independent' reported.

Gradwell also advised passengers not to go indoors on arrival but get out in the daylight - as it is the quickest way to adjust your body clock.

He warned against sitting still for the entire flight, or rejecting the water offered by the flight attendants, as moving your legs and feet and staying well hydrated are the best defence against deep vein thrombosis, a hazard of long haul flying.