Simulate Joule Heating in a Wire and plot temperature Distribution

I'd like to simulate joule heating in a PVC covered copper wire in air. Then plot the radial temperature distribution across the wire and insulator.

I'd appreciate any advice should it be 2D, 2D axisymmetric? Are any ready made models available?

Any step by step advice on how to build such a model?

I know this result can be arrived at algebraically but this is intended to be a learning exercise.

Thanks