How altitude effects aerodynamic heating? To what extent temperature distribution is effected by aerodynamic heating ? (for a sharp cone at M=2)

Air density and temperature change with altitude. This in turn changes the speed of sound, viscosity. For a given velocity, Mach number and Reynolds number will be different at different altitude. This will determine whether the flow over the surface is turbulent or laminar. A quick visit to the chapter of boundary layers in compressible flow, H. Schlichting's book of Boundary Layer Theory (Mcgraw-Hill Book)will give you some quick information (theory and charts). Common sense information: Supersonic Transport and fighters have been flying at Mach 2 routinely. Black Bird flying at Mach 3.5 requires special attention due to surface heating.