The 15-minute city in a warming Global South

The 15-minute city has gained global traction as a model for sustainable and equitable urban living, grounded in the assumption that spatial proximity facilitates accessibility. This viewpoint piece argues that in heat-stressed contexts, particularly within the Global South, this framework requires significant reframing to remain effective. We contend that accessibility is determined not only by physical distance but also by the thermal safety of the environment in which mobility occurs. By introducing the concept of usable access, this paper calls for a shift from purely spatial metrics of walkability to performance-based evaluations in warming urban environments. We advocate for a planning approach that prioritises the comfort and safety of vulnerable populations to ensure the 15-minute city remains an inclusive model for climate-adapted mobility.