What drives adaptive behaviours during heatwaves? A systematic review with a meta-analysis

Global warming will lead to more frequent and intense heatwaves across all regions of the world in the coming decades. Adaptation at the individual level plays a key role in helping populations cope with these extreme events. This study undertakes a systematic review of the academic literature on the determinants of heat-adaptive behaviours (HABs) following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A Boolean algorithm was used on two online databases (PubMed and Web of Science Core Collection) to retrieve 73 relevant, quantitative, peer-reviewed papers. All included studies focus on high-income economies (N = 48) or middle-income economies (MIEs, N = 25). A meta-analysis was performed on 34 studies using a random-effects model, with an emphasis on heat-related perceptions (perceived efficacy, risk and threat) and heat-related knowledge (HRK), as these variables are the most likely levers of behavioural change. Perceived efficacy, HRK, perceived threat and gender (i.e. being female) are positively associated with the adoption of HABs. A moderation analysis reveals heterogeneity in the effect of these variables by country income group, with low HRK and perceived threat constituting stronger barriers to HABs in MIEs. This study also highlights various gaps in the current literature, regarding the populations studied, the statistical methods used, and the lack of standardization of HABs and perception concepts.Heat-adaptive behaviours (HABs) are influenced by both psychological and non-psychological factors. Information and communication campaigns may be designed to influence the determinants of psychological factors and use them as adaptation levers.Policymakers should implement information campaigns to underline the characteristics and adverse health effects of heatwaves, as well as reminding people of ways to cope with heatwaves, especially in middle-income economies (MIEs).Information and prevention campaigns in MIEs should clearly highlight the frequency and severity of the health hazards associated with heatwaves in order to improve public awareness of these risks.Information campaigns based on simple infographics showing the most effective HABs and reminding people of the efficacy of HABs to reduce heatwave health risks may be especially impactful in high-income economies.