Apparently you shouldn't put a teabag into the bin when it's really hot, as it could start a fire.

I work for a significant scandinavian phone manufacturer as an RF engineer, so I may be able to shed a bit of light....

The most probable cause for a fire starting with a mobile phone is if it gets dropped and the battery is punctured. A lithium ion battery will go on fire quite nicely if you stab them with a screwdriver, something I've witnessed at first hand. {safety disclaimer} I DO NOT RECOMMEND DOING THIS!!!! There is a potential for explosion. In addition if the battery came off and the terminals were shorted and the saftey circuit in the phone did not trip, sparking could occur. I imagine NIMH would spark up quite nicely too though I've never worked with them. In fact some of the old 9V square alkaline batteries were particularly good at going bang if you shorted the terminals.

While this is a bit of a long shot to happen it is much more likely than a spark due to RF coupling. Mobile phones produce a maximum power of 2W in a carefully controlled burst to minimise interference. I am certain you would need lots more power to get things to spark.

To second what QNH 1013 said I would consider torch batteries to pose a much more significant risk....

Cheers
John

Mobile Phones and Things that go Bang
 

The only trouble I ever had with the phone was when departing Luton on a VFR north to Pirton, the familiar "dik dedik dedik ...." sounded in my headphones .... just as the tower man said ... "we've just lost your transponder signal". Turned phone off quick and recycled transponder. Problem went away.

As I was reconstructing Luton at the time, I used my mobile everywhere all of the time. And all the ground staff used them all over the apron as well (can't speak for the bowser drivers)

I always tell my pax now to make sure the phones are off.

BUT .. on the subject of things that go bang .... why do we earth aeroplanes before refuelling, when we don't do it to cars on the Shell forecourt ???? I've asked load of folk but never had a decent reply.

Most responses seem to be based on the "hear-say" type of report that started this thread.

Anybody able to explain ????