Thermal and mechanical processes in aquifers are of increasing interest for hydrogeological analysis, for development of innovative field and laboratory experiments. Both in research and in practice, the realistic characterization of subsurface flow and heat transport, observations of induced or natural variations of the thermal regime, the seasonal and long-term development of thermal and mechanical conditions in aquifers, and heat transfer across aquifer boundaries are focal points. This also includes the role of groundwater in the context of geothermal energy use for predicting the long-term performance of geothermal systems, and integration in urban planning. There are many ongoing research projects studying heat as a natural or anthropogenic tracer, and which try to improve thermal response testing in aquifers. Such techniques are of great potential for characterizing aquifers, flow conditions, and crucial transport processes, such as mechanical dispersion. Understanding the interaction of hydraulic, thermal and mechanical processes is a major challenge in modern hydrogeology. Deep underground constructions, tunnels, CO2 storage, hydro- and enhanced geothermal applications are prominent subjects. We invite contributions that deliver new insight into advances in experimental design, reports from new field observations, as well as demonstration of sequential or coupled modeling concepts. The session aims to provide an overview of the current and future research in the field, covering any temporal or spatial scale, and seeks to address both separate and coupled processes.