Protein activity can be precisely regulated via subtle changes in temperature using heat-sensitive switches. Underlying this capability is a novel modular design strategy developed by researchers at the Institute of Pharmacy and Molecular Biotechnology of Heidelberg University. The strategy allows the integration of sensory domains in various proteins regardless of function or spatial structure. This new Heidelberg approach in the field of thermogenetics is broadly applicable and opens up new possibilities for precise, non-invasive control of different cellular processes.