Right GB, it's as well to warn people. I've been using Lipos ever since they became available.
I do take sensible precautions, but there's no need to be paranoid about it. I always unplug them after using.
Shorting out the terminals or puncturing the cells kills 'em quickly and have been known to fire them up - literally.
In (what, must be about 15-20 years using them), I've punctured one accidentally, it didn't flame, but got VERY hot and exuded some rather pretty smoke.
Out of the dozens I've used, I've had a couple that inflated a bit, and a few that lost their girlish laughter for no apparent reason.
You need a good charger, one that's made for the job, (Lipos) but they're cheap enough nowadays. Lipos are very sensitive to charge rates etc, so you can't just use a car-type charger that's made for for lead acid batteries. Oh, and overdischarging them will kill them.