Satellite-derived Land Surface Temperatures Strongly Mischaracterise Urban Heat Hazard

Escalating urban heat, driven by the convergence of global warming and rapid urbanization, is a profound threat to billions of city dwellers. Effective action to address this challenge requires reliable metrics and data, which are often not readily available. Consequently, the science directing urban heat adaptation is strongly influenced by studies that use satellite-based land surface temperature (LST), which is globally available and address data gaps in cities, particularly in the Global South. Hence, LST now often serves as the default lens through which many cities view their heat realities. Yet this lens is fundamentally misfocused. LST, is a poor surrogate for near-surface air temperature, physiologically relevant human thermal comfort, or direct human heat exposure. This flawed practice leads to issues for several downstream use cases by inflating adaptation benefits, distorting the magnitude and variability of urban heat signals across scales, and thus misguiding urban adaptation policy. Drawing on remote sensing, climate science, and governance theory, we clarify what LST does and does not represent and expose where its use drifts most dangerously across disciplines. We argue that satellite-based LST must be treated as a distinct indicator of surface climate, which, though relevant to the urban surface energy budget, is frequently decoupled from human-relevant thermal impacts. We then advance practical guardrails and principles for using LST wisely, alongside a Surface-to-Society framework to re-align urban heat governance with metrics grounded in human heat exposure. We argue that the global community must urgently pivot from cooling pixels to cooling people.