Six students scooped the audience award after joining forces with the Hamburg Institute for Innovation, Climate Protection and Circular Economy (HIICE), a subsidiary of Stadtreinigung Hamburg, to find solutions to climate-related overheating in housing estates. Concrete buildings store heat and raise the temperature in the city during dry summers. The young scientists developed prototypes of green concrete enclosures for dustbins and inner courtyards to make cities more resilient. A mix of indoor heat and rainwater outside creates a micro climate in which plants grow alone and cool down.