The Cold Tube is a research and demonstration project to explore new applications for selective low-cost polymers that universally enables radiant cooling to occur in hot and humid environments without dehumidification and the risk of condensation. The Cold Tube concept allows the recursive relationship between design and radiant cooling to flourish, enabling radically new indoor and outdoor urban typologies and modalities, fundamentally based on materials engineering, thermodynamics, and design. The project will seek to investigate the potential implications of wider adoption of the technology in hot and humid climates, both through an expanded design-driven demonstration in a real-world scenario, and the development of calibrated predictive models of energy and comfort for integration with larger urban-scale heat island and Outdoor Thermal Comfort (OTC) models. The project is a project of ETA Lab (UBC) in collaboration with the Singapore-ETH Centre, CHAOS Lab (Princeton University), the Center for Built Environment (UC Berkeley), and the Chair of Architecture and Building Systems (ETH Zurich). The project is funded by the Singapore National Research Foundation.