Assessing demographic and socioeconomic susceptibilities to heatwaves in the Southeastern United Kingdom

• Heat vulnerability factors correlate and require collective mitigation. • PCA identified poverty, elderly, unemployed, work-distance as major factors. • Most areas are at Level 3 of 6 for these major factors. • Cumulative: moderate vulnerability (11-12/20), requires comprehensive strategies. • Suggest cooling centres, transport aid, multilingual risk communication and home visits. As climate change intensifies, the frequency and intensity of heatwaves are rising to pose significant health risks. Population vulnerability, influenced by socio-economic and demographics factors, is a widespread concern. We analysed heat vulnerability by demonstrating usefulness of principal component analysis on recent, localised census data at lower super output scale for vulnerability factors such as poverty, access to cooling facilities, age, and gender for a non-city yet highly heat risk vulnerable case study of Surrey, UK. Four major factors (poverty, elderly population, unemployed students, daily commute) were identified, creating a cumulative Heat Vulnerability Index, aiding in prioritising interventions and mapping vulnerable areas. Mapping revealed most areas had a moderate vulnerability level of 3 out of 6 for individual major factors, with cumulative scores ranging from 11 to 12 out of 20. The study emphasises the interconnectedness of vulnerability factors and highlights the applicability of the approach beyond Surrey. The demonstrated methodology provides a valuable template for vulnerability assessments in regions facing similar challenges and have its up-to-date effective heat action plan underlining the importance of tailored strategies for comprehensive heat risk management (e.g. cooling centres, transport aid, multilingual risk communication and home visits). Policymakers can utilise the insights gained to develop targeted measures for vulnerable populations and manage heat-related issues effectively on a global scale.