If you're onboard a for a long , it can be tempting to relax with a cup of coffee, tea or even water if you're feeling dehydrated. However, according to one former flight attendant, doing so could make you sick.

In a video which racked up more than 500,000 likes, former Kat Kamalani shared her top tips with her followers. Kat said: "Never ever, ever, ever consume these products on an aeroplane from a former flight attendant. Rule number one: Never consume any liquid that is not in a can or a bottle.

"The reason is that those water tanks are never cleaned, and they are disgusting.

"Talk to a flight attendant, we rarely drink the coffee or tea, they come from the same water tank, and so when you're drinking that coffee, tea or tap water, it comes from that hot water, and it's absolutely disgusting.

"They are rarely cleaned unless they are broken... and they're by the lavatories.

"So, pro tip for all you parents - never ask for hot water and put it in your babies bottle, ask for a bottle of water on the side and hot water in a cup, then make your baby a bottle with the bottle water and put it in the cup to heat it up."

The video racked up more than 500,000 likes, with more than 4,000 comments from frequent travellers.

One comment from Stells read: "You guys should just clean them every so often, that's so messed up."

Another from Jerry said: "Why don't you guys fix this if you know about it? This is irresponsible."

It's also generally recommended to avoid drinking alcohol on flights as it can make passengers dehydrated, not ideal if you're on a long-haul flight.

Stick to bottled water, orange juice or even herbal teas with low amounts of sugar to stay hydrated.