Purpose <p>This study presents a theoretical framework to analyze the dynamic thermoelastic response of a solid cylinder containing microscopicvoids under a sudden thermal shock at its lateral surface. The core contribution is a unified model that integrates higher-order time-derivative heat conduction with spatio-temporal Klein-Gordon nonlocal elasticity in a porous medium. This new formulation simultaneously captures three key phenomena: the wave-like nature of thermal propagation, the material’s intrinsic microstructural effects via a characteristic length scale and a temporalinertia parameter, and the active role of voids as a dynamic internal variable.</p> Methods <p>To obtain precise time-domain solutions, the governing equations are solved using a rigorous hybrid methodology that combines analytical techniques in the Laplace transform domain with efficient numerical inversion.</p> Results <p>The key finding is that microscopic voids act as a powerful internal damping mechanism. Their presence and concentration substantially reduce temperature, displacement, and stress magnitudes throughout the cylinder, resulting in a noticeably smoother and more attenuated wave propagation. This enhanced damping behavior, predicted uniquely by the proposed model, offers critical insights for the engineering design of advanced lightweight porous materials.</p> Conclusion <p>These findings may inform the design of high-performance components where thermal shock resilience is important, such as in aerospace, automotive, nuclear, and biomedical fields.</p>