The wheels and rails of the train, tram etc. are often verified from their microstructure and plastic deformation, which usually appear in the outer layer of a wheel and rail, to analyse the causes of geometrical defects by monitoring the applied loads and variation of the temperature as suggested in the literature. This paper studies the effect of thermal stress applied with variations of the loads in contact on wheel/rail for the tramway, tracking through the state of the rail to discover the causes of geometric defects started by temperature variations and loads, and applying these variations of temperature and loads to know its resistance to these climatic conditions. 3D model of temperature distrubtion and heat flow in the wheel and the rail ER6 and ER7 has been developped using the finite element method based on the COMSOL Multiphisics.