Hadrons and correlation function modification in hot hadronic matter

For various hadrons propagating in hot hadronic matter we calculate the momentum-dependent optical potentials (both real and imaginary parts), using experimental data on binary collisions. Due to the non-trivial compensations, hadron modification is rather small, except probably very close to T_c. Jumping over the phase transition region, we consider quark propagation in the plasma at high T. Another interesting compensation effect is found, excluding the contribution of states with energies E ≪ T. As a result, mesonic (baryonic) correlation functions decay with decrease x as exp (-nπTx) with n=2,3 being a number of quarks. We also make a critical discussion of applications of QCD sum rules at finite temperatures, and also consider recent lattice data.