The joint impact of summer heatwave intensity and heat-vulnerability factors on adaptive responses: A case study using England's National Travel Survey

Since the mass casualties of the 2003 European heatwaves, extreme heat has emerged as a pressing environmental and public health issue across Europe. The need for effective adaptation policy is growing as heatwaves increase in intensity, frequency, and duration, yet little is known about the social processes which shape heat exposure and limit people's capacities to adapt. Focusing on England as a Northwestern European case study, this study examines people's adaptations to summer heatwaves from 2007-2019 and the heat-related vulnerability factors shaping their responses. The analysis uses a multi-level modelling approach which links England's National Travel Survey with ERA5 climate re-analysis data to examine patterns of stay-home and medical-trip-making. Responses are examined according to heatwave intensity (moderate and extreme) and according to individual and household-level factors related to socio-demographics, health, employment, housing, and spatio-temporal context. The impacts of heatwaves on shelter-at-home and medical-trip making are found to vary with their intensity but are strongly mediated by the social characteristics of those exposed. People widely shelter at home during extreme heatwaves yet are slightly more active during moderate ones; adaptations which differ according to heat-vulnerability factors. Specifically, people working or having worked in manual/routine occupations are less likely to shelter-at-home during extreme heatwaves, older individuals remain more active during moderate heatwaves while those with mobility difficulties are more likely to withdraw into their homes, and medical services are sought more by people who rent their homes and less by non-white individuals. This study highlights how wide-ranging social factors mediate people's exposure and adaptive responses to summer heatwaves in a Northwestern European context.