Cosplay help on NOT setting myself on fire

I need a little bit up help with electrical help on my gundam cosplays. Currently I'm working on the EZ 8 Rx-78 [G] my first gundam cosplay went well until, for some reason the 9v battery cap super heated the battery and set the inside of my helmet smoldering from its heat. I used a parallel circuit wiring to the computer fans and the LEDs they worked fine in the test runs but as soon as I go to otakon and put it on, wham my head was on fire. What do I do to avoid this or was it just faulty radio shack stuff again?

aside from the usual "well don't set yourself on fire" "stop being flammable" and the ever popular "haha" I must know a few things... 1) materials of the helmet 2) TYPE of fans 3) type of wires 4) number of fans 5) number of connections in the circuit 6) number of batteries I have an ODST helmet that uses fans and I was working on lights (gave up on that part as I couldn't figure out where to put them then lost interest in the project...helmets done though :) )

Thank you Maverick I'm going to have to check over my resistor math again or just go over separating the LEDs and the fans to different circuits