Airway

If you sleep on your back it's easier for your upper airway to be obstructed because your tongue, uvula, etc. slip towards the back of your throat.

Because it inflames upper-airway tissues, smoking often leads to obstructive sleep apnoea. Alcohol and sedatives can worsen apnoea as well; acting as muscle relaxants, they make the airway smaller.

Felix's airway was obstructed.

The burners on gas stoves release pollutants including nitrogen dioxide, a key element in smog that can irritate airways and may contribute to the development of asthma, according to the U.S. Environmental Protection Agency.

David Williams, a scientist who evaluates antivenoms for WHO, says the biggest risk to people who are bitten by these snakes is paralysis, "which can prevent them from being able to control their airway and breathing and they can potentially suffocate and die as a result of that."

But British Airways Flight 112 made the trek in under five hours, setting a new record for the fastest subsonic commercial flight across the Atlantic Ocean.