Confined test blocks of Hollington sandstone were exposed to direct heating by an infrared lamp within an open-topped cabinet. Temperature and moisture profiles were monitored as retreat of the test blocks at 10 mm intervals created an extending shadow zone on the surface. Stone surface temperatures were reduced by block retreat, and subsurface thermal gradients did not extend so deep into the stone, but remained steep; high rates of surface temperature changes were recorded under conditions of direct and indirect heating. High stone moisture content resulted in subdued surface temperature ranges and reduced depth of thermal gradients. The rate of moisture loss from subsurface layers decreased as the test block retreated into the shadow zone. Results suggest that stone decay in caverns may be promoted by microenvironmental conditions, particularly related to their morphology.