Risk perception and protective behaviors to heat waves: An application of the health belief model

Heat waves are among the most critical climate change threats, with serious implications for human health. Although protective behaviors can mitigate their impacts, individuals do not consistently adopt them, particularly when the threat is novel and its consequences are not fully recognized. This study examines how different dimensions of risk perception influence protective behaviors during heat waves by applying an extended version of the Health Belief Model (HBM). A stratified survey of residents in Santiago, Chile ( n = 782), was conducted during the summer of 2024. Logistic regression models compared the explanatory power of the original HBM with an extended version including two additional dimensions of risk perception: worry and perceived future harm. These variables capture affective and anticipatory threat evaluations emphasized in Protection Motivation Theory (PMT), allowing a broader conceptualization of risk perception within the HBM framework. Findings show that behavior-specific evaluations of benefits and barriers were the factors most consistently associated with protective behaviors. Worry emerged as a key emotional determinant, whereas perceived susceptibility exerted limited influence. Overall, the results underscore the value of incorporating affective and anticipatory dimensions of risk perception when designing public health strategies to strengthen adaptive responses to heat waves.