How to isolate a battery pack from a controlled short?
so i am trying to make a portable electric stove and am trying to isolate the heat coil from the battery pack itself i know there is a way of doing this however for the life of me i cant remember how it works or what it is called. any help would be greatly appreciated!
 so there was some confusion on what i am trying to accomplish. i keep burning up batteries (when i say burning up i pretty much mean just that.) they don't like being connected to circuit that's sole purpose is to short out (albeit in a controlled way.) i wanted to isolate the batteries from the part of the circuit that is shorting to create the heat. if that still doesn't make sense or you think my problem might be something else entirely, please let me know.
also so you know what my circuit looks like. it is a battery box power supply soldered to my heat element as well as a variable resistor to allow me to change heat output.
hopefully that helps clarify.