It would probably only do that if the LiPo sack was somehow damaged. I haven't heard of a spontaneous LiPo explosion, but as you said, anything is possible. If you ever damage a LiPo, dispose of it properly and immediately. It is far cheaper to replace one LiPo than it is anything the LiPo may destroy on it's path to the grave.
I have had this Twenty 11.1V 2150mAh LiPo on my computer desk for the past year or so without any problems. It fluctuates in temperature just like my room (freezing to ZOMG where's the A/C!?).
Now that I mention it, I should probably peak it.. and put it back in it's container..
Cheers,
Kyle.