Plastic deformation of crystals and glasses produces internal strains (stresses), which change their energy and other thermodynamic properties. On annealing, these stresses decrease at a rate faster than the structure relaxes toward the equilibrium state. Mechanism of such relaxations in crystals differs from that in glasses and it also differs for glasses of different types. In all cases, the energy related properties decrease with time isothermally and on heating, resembling the structure relaxation of a stress-free glass. We consider these features and argue that kinetics of enthalpy loss with time yields the rate constants of the stress release and of the structure change, and not the viscosity determining a-relaxation time. Since thermal cycling does not recover the enthalpy from internal stresses, a glass with stresses has neither a glass-softening temperature, T-g, nor a fictive temperature, T-f. Plastic deformation would not rejuvenate a physically aged glass to the properties of its un-aged state. The Prigogine-Defay ratio can be extended to all T(f)s, and used to investigate the effect of distribution of relaxation times on its value, but it can not be defined for an internally stressed glass. After discussing the effects of annealing on the heat capacity and DSC scans, we conclude that on slow heating, glass with deformation-induced stresses would show two exothermic minima, and normal glass would show only one such minimum. Temperature-modulated scanning calorimetry would also distinguish an internally stressed glass from an equally high-enthalpy, stress-free glass. Enthalpy matching procedure would yield inaccurate Tf value of a plastically deformed glass, but not of a hyperquenched glass. Phenomenological analysis given here has consequences for interpretation of the calorimetric changes observed on heating the shear-amorphized, as well as pressure-collapsed states of crystals. (C) 2014 Elsevier B.V. All rights reserved.