Batteries on planes could pose increased risk of catching fire on flight, it has been revealed.
A recent estimate said that the average small plane carrying 100 passengers could have 500 lithium batteries on board when you tot up all the watches, laptops, cameras, e-readers, tablet computers and suchlike.
Now the UK's safety regulator, the Civil Aviation Authority (CAA), has told the BBC that the huge growth in people carrying lithium batteries on aircraft poses a growing fire risk.
Lithium batteries look harmless enough, but they pack a hell of a punch if they overheat.
The CAA has been working with its US counterpart, the Federal Aviation Administration (FAA), to produce a series of videos showing aviation professionals and the public how to pack batteries safely and what to do if they happen to smoulder or even catch fire.
The films will eventually go online, to be watched by cabin crew, luggage handlers, members of the public and people sending things in the post (don't forget that a lot of post goes on aircraft, even within the UK, so ask at the Post Office if you are sending a device with a lithium battery inside).