<p>Heatwaves present an escalating threat to public health, with impacts influenced not only by heatwave intensity but also by sociodemographic disparities in exposure and adaptive capacity. Most existing studies analyze heat exposure and adaptive behaviors separately, obscuring the accurate identification of vulnerable groups characterized by both high exposure and limited adaptation. Furthermore, the role of media-based heatwave warnings in shaping adaptive behaviors across different populations remains insufficiently examined, constraining the design of targeted interventions. This study draws on survey data collected through snowball sampling from 562 Chinese respondents between October and November 2023 to examine sociodemographic differences in outdoor heat exposure and three prevalent adaptive behaviors: visiting cooling centers, deploying sunshades, and using air conditioning. It further examines how these behaviors are associated with risk perception (measured by perceived heatwave severity) and media exposure across sociodemographic groups. Logistic regression reveals the uneven exposure risk: middle-aged, moderate-income commuters and non-local outdoor workers exhibit the higher exposure risk. Regarding adaptive behaviors, education level strongly predicts the cooling center use. Sunshade utilization correlates with gender and local residency, while air conditioning use varies by income and perceived heat severity. These findings emphasize the need for tailored interventions: media-optimized warnings for elderly populations, heatwave subsidies for outdoor and low-income workers, and expansion of cooling infrastructure in urban heat hotspots. By delineating vulnerable groups and their distinct adaptive patterns, the study supports more equitable and effective governance of heatwave risks.</p>