Extreme heat is one of the most pervasive and inequitable climate risks faced by cities, yet thermal comfort remains weakly operationalized within urban climate governance. This paper examines how outdoor thermal comfort is addressed in the Climate Action Plans (CAPs) of ten C40 cities spanning diverse climatic zones and socioeconomic contexts across the Global North and Global South. Using a qualitative content analysis, the study evaluates whether and how thermal comfort is framed as a policy objective, the metrics and indicators adopted to assess heat stress, the portfolios of urban cooling interventions proposed, and the extent to which equity considerations are embedded in planning and implementation. The results show that thermal comfort is rarely treated as an explicit and measurable objective in CAPs. None of the analysed plans systematically operationalize outdoor thermal comfort through thermophysiological indices based on the human energy balance, such as the Universal Thermal Climate Index (UTCI) or Physiological Equivalent Temperature (PET). Instead, the plans more commonly rely on hygrometric or operational heat indicators, such as air temperature thresholds, tropical nights, overheating references, heat emergency triggers, or qualitative descriptions of heat risk. Distinct regional patterns emerge across the ten CAPs analysed. All five Global North cities analysed prioritize technologically oriented cooling strategies, including reflective materials, building efficiency measures, and infrastructural interventions aimed at reducing urban heat exposure. In contrast, all five Global South cities emphasize nature-based cooling interventions, such as urban greening and ecological corridors, while also integrating community-oriented adaptation strategies focused on vulnerable or informal settlements. Across both contexts, equity is widely acknowledged but seldom operationalized through spatial targeting, monitoring frameworks, or enforceable safeguards. The study highlights the need to move beyond descriptive recognition of heat toward the explicit integration of outdoor thermal comfort into CAPs. By combining standardized metrics, spatially targeted cooling strategies, and equity-oriented governance mechanisms, CAPs can become more effective instruments for protecting public health, enhancing urban livability, and advancing climate justice under growing heat extremes.
Monteiro et al. (Thu,) studied this question.