Now put together the female connector with the switch and fuse housing, and end it all with a ring connector on each end. To brake it down, take two lengths of your thick wire. Attach a ring terminal on one end of each wire. Now, connect one of those wires to the fuse housing, and the other wire to one of the terminals on the switch. Now attach another wire to the other terminal on the switch and have that go to one side of your female connector and the other end of your fuse housing to the other side of your connector. Don't worry, I drew a diagram. And there you have it, your own heated pants. Now you can do the same thing for any other article of clothing you want to electrify.
but, i have to tell you that this is the most incorrect way to display an electric chain(read here the correct way), never-mind, you used the tags to explain what's on the image.
about the isolation on connections you can you termo-compressible tubing( it compress itself wen you heat it with a pistol)