Sounds like you just pulled too much current for the entire system to handle. This will definately heat up EVERYTHING.

Just overheating them once may not destroy the battery. But I would definately check everything to be sure I didn't exceed the batteries capability. You should never draw more than the battery's rated current for any length of time. They will definately overheat, even 20C Cells will get pretty warm if you push them to the 20C for any length of time.

And I as well just have my packs on a shelf. Do carry them to the field in a fireproof box, in case of getting them banged up in the car. Never had one cause a problem except when I forgot to set the charger correctly, and in a crash.

So now I use an "idiot proof charger" and that part went away. The "Crash" thing - Oh Well!