  We compute the quantum correlation (quantum discord (QD)) and the
entanglement (EoF) between nearest neighbor qubits (spin-1/2) in an infinite
chain described by the Heisenberg model (XXZ Hamiltonian) at finite
temperatures. The chain is in the thermodynamic limit and thermalized with a
reservoir at temperature T (canonical ensemble). We show that QD, in contrast
to EoF and other thermodynamic quantities, spotlight the critical points
associated to quantum phase transitions (QPT) for this model even at finite T.
This remarkable property of QD may have important implications for experimental
characterization of QPTs when one is unable to reach temperatures below which a
QPT can be seen.
