  We present a novel numerical method for the evaluation of dynamical response
functions at finite temperatures in one-dimensional strongly correlated
systems. The approach is based on the density-matrix renormalization group
method, combined with the finite-temperature Lanczos diagonalization. The
feasibility of the method is tested on the example of dynamical spin
correlations in the anisotropic Heisenberg chain, in particular it yields
nontrivial results for the critical behavior in the isotropic case.
