Protecting low power cables from heat
First check the cable you have.  82C isn't really all that hot, being well under the boiling point of water.  Is there really a problem with that cable?

If you've got insulation not rated for 82C, then you do need something else.  You don't need anything exotic, like teflon, at that temperature.  You also don't need a fancy "cable".  Since it's only carrying power, a simple twisted pair with the right insulation will be sufficient.  There should be lots of choices out there.