  We review several properties of thermal states of spin Hamiltonians with
short range interactions. In particular, we focus on those aspects in which the
application of tools coming from quantum information theory has been specially
successful in the recent years. This comprises the study of the correlations at
finite and zero temperature, the stability against distant and/or weak
perturbations, the locality of temperature and their classical simulatability.
For the case of states with a finite correlation length, we overview the
results on their energy distribution and the equivalence of the canonical and
microcanonical ensemble.
