They are going to fail like anything else when you don't take care of it.. Take an nimh, don't take care of it, it will blow a huge hole in whatever it is touching. Same with a lipo.
All you need is either a low voltage alarm, which will have an ear piercing audible tone when the cells hit the set lower limit. Very easy to hear.
Or just get an esc with built in Low Voltage Cutoff (LVC) and you will be fine, the ESC will stop you automatically.
If you are REALLY scared of them, charge ALL of your batteries in an ammo can.
Best advice would be to get over your fear, you're missing out on a far superior battery technology in lipos.