Evolution of Temperature in Abaqus model applying only Temperatures on the structure?

[barlume]

I am not an expert in thermo-mechanical problems and am trying to solve a thermo-mechanical problem in Abaqus.
However, I have some problems with the use of Temperature.
My structure has a starting temperature of 300K and, suddenly, one face suffers an increase of Temperature up to 600K.
I would like to see the evolution of the temperature in the structure, but it stays equal to 300K on all the structure and 600K only on the frontal face.

I am using thermo-mechanical elements and I defined specific heat, conductivity, expansion coefficient and so on.
I defined the initial T with these lines in the main part of the INP file (Set-9 is the entire structure and T_in is the starting Temperature):

** PREDEFINED FIELDS
**
** Name: Predefined Field-1 Type: Temperature
*Initial Conditions, type=TEMPERATURE
Set-9, <T_in>


I defined the new T with boundary conditions (T_fin is the final Temperature at one side and OP=NEW returns only at the initial conditions the rest of the model, so it is useless here):

** Name: BC-1 Type: Temperature
*Boundary, OP=NEW
Set-10, 11, 11, <T_fin>

What should I do to obtain the change of distribution of T?
I do not have energy sources or similar, so I do not think I can simulate an exchange of heat.
Should I define an evolution of T in the INP file (but how can I choose meaningful parameters?)?
I would like to exploit the thermo-mechanical elements and define only the Temperatures, if it is possible.

Thank you very much for your attention
Gabriele