This "UMATH subroutine in ABAQUS" package teaches you how to define the thermal constitutive behavior of the material as well as internal heat generation during heat transfer processes. This subroutine needs to define a different variable including internal thermal energy per unit mass, a variation of internal thermal energy per unit mass with respect to temperature, heat flux vector, variation of the heat flux vector with respect to temperature, and variation of the heat flux vector with respect to the spatial gradients of temperature. This training package tries to teach how to use this subroutine by using various thermal examples.