From Enduring to Adapting Heat Risks: Characteristics of Responses, Group Differences, and Spatial Distribution of Urban Residents' Subjective Expenditures for Heat Adaptation

Economic expenditure incurred by urban residents to alleviate heat-related discomfort constitutes an observable economic manifestation of their adaptive responses to heat risk. Focusing on the core area within Beijing’s Sixth Ring Road in a megacity context, this study integrates field-based questionnaire surveys with heat exposure data to systematically examine the response characteristics, population heterogeneity, and spatial patterns of residents’ subjective adaptive expenditure under heat conditions. The results indicate that residents’ subjective adaptive expenditure is more strongly associated with subjective heat risk perception than with objective heat exposure risk. A pronounced mismatch exists between objective heat exposure and subjective adaptive expenditure: for every 0.1-unit increase in heat exposure risk, the average monthly subjective adaptive expenditure decreases by 142.99 CNY, while a 1 °C increase in the self-reported temperature threshold triggering adaptive behavior corresponds to an average monthly reduction of 11.70 CNY. The structure of subjective adaptive expenditure shifts from short-term consumption-oriented spending toward maintenance-oriented spending as heat exposure risk increases. Expenditures on protective clothing and equipment, electricity, and adaptive food items are more sensitive to changes in heat exposure risk, whereas health-related expenditures such as disease treatment exhibit relatively high stability. Heat-response patterns among residents display clear clustering characteristics and can be classified into four typical groups: “high exposure–low impact–low expenditure,” “low exposure–high impact–high expenditure,” “medium exposure–medium impact–medium expenditure,” and “low exposure–low impact–low expenditure.” Age, household registration status, and gender emerge as key attributes distinguishing these groups. The total subjective adaptive expenditure of urban residents in Beijing is estimated at approximately 112 million CNY per month, exhibiting a spatial pattern characterized by higher values in central areas and lower values toward the periphery. This study reveals the economic expenditure response associated with adaptive behaviors of urban residents under heat conditions, providing quantitative evidence to support differentiated heat risk management and targeted adaptation policies.