In message , Brian Gaff
writes
Well, the small ones are pretty bomb proof. Normally they need a direct
short to burst into flames, as in the famous video where a nail gun is used
to do the deed. Just heating, unless its really far too much for the rest of
the device is unlikely to do it as many do run hot if charged quickly. Can
you not replace the batteries. I know that they do not last for ever, as
they put the same ones in some mp3 players as well.
Brian

Brian, There are pictures of the type I have at

http://tinyurl.com/y9wmcd74

They show a camera whose battery has left this earth.

This cam looks difficult to get into, and, behind the windscreen in the
sun, it gets too hot to touch. It is said to have a battery which shuts
down at over 70 degrees C, but looks standard. However, there are
warnings about cheap copies of these batteries, and the ones on ebay and
elsewhere would all have to have the connector from the old batt
swapped.

The camera seems to work OK with bad battery, soit is really a question
of whether it would be safer to try to crack the thing open and pull the
battery completely or not to bother.
--
Bill