Resonant frequency +set stress and temperature

How way I will find resonant frequency my structure? I use to Structural mechanic modul, then Solid mechanics and then Frequency domain-Modal or Eigenfrequency?
I need to specify these parameters: stready state temperature and mechanical stress.

I dont know how I set into the model initial temperature and mechanical stress.
Domain ----- 350 deg. celsius and 100MPa

Thank you for your valuable advice