Extreme heat, whether occurring as single or multiple anomalously hot days and nights, poses direct and indirect impacts to human health and to built and natural systems. Direct impacts include heat-related illnesses (e.g., heat cramps, heat exhaustion, heatstroke) and mortality. Indirect impacts include exacerbations of other hazards, like drought and wildfire, as well as stressors like air pollution. Adaptation to extreme heat can take many forms, such as in behavioral, institutional, infrastructural, technological, and ecosystem-based change. It can also take place on varying levels or spatial scales, requiring different resources and time frames to implement. Given that heat-related illnesses and mortality are often preventable when people are able to take protective action, one potentially near-term, relatively cost-efficient, and effective adaptation is to successfully inform the public about heat risk. This requires not only communicating with the public about heat risk when it is imminent (i.e., institutional adaptation), but also educating the public about heat risk such that it can interpret and make use of the messaging received (i.e., behavioral adaptation). The field of risk communication offers recommendations and guidance that can help inform heat risk communication, for example related to warning source and channel as well as to message purpose, content, and style. Similarly, the field of health literacy, and in particular the newly conceptualized “climate and health literacy,” offer proposed pathways that can be leveraged to help educate the public about heat risk. Bridging these two fields and the actors (or practitioners) within them therefore promises to be fruitful in the reduction of heat-related morbidity and mortality and in improving overall health outcomes in vulnerable populations across the globe. Critically, however, to be effective, both risk communication and climate and health literacy must be designed with direct knowledge of and engagement with target audiences. Accordingly, actors within these fields should collaborate not only with one another but also with the specific audiences they intend to serve.
Article
Bridging Risk Communication and Health Literacy to Improve Health Outcomes Related to Heat
Kristin VanderMolen and Benjamin Hatchett
Article
The Impact of Moisture and Temperature on Human Health in Heat Waves
Michael Wehner, Federico Castillo, and Dáithí Stone
Extremely high air temperatures are uncomfortable for everyone. For some segments of the population, they can be deadly. Both the physical and societal aspects of intense heat waves in a changing climate warrant close study. The large-scale meteorological patterns leading to such events lay the framework for understanding their underlying causal mechanisms, while several methods of quantifying the combination of heat and humidity can be used to determine when these patterns result in stressful conditions. We examine four historic heat waves as case studies to illustrate differences in the structure of heat waves and the variety of effects of extreme heat on humans, which are characterized in terms of demographic, geographic, and socioeconomic impacts, including mortality and economic ramifications.
Weather station data and climate model projections for the future point to an increase in the frequency and intensity of extreme heat waves as the overall climate gets warmer. Changes in the radiative energy balance of the planet are the principal culprit behind this increase. Quantifying changes in the statistics of extreme heat waves allows for examination of changes in their potential contribution to human health risk. Large-scale mortality during heat waves always occurs within a context of other factors, including public health policy, rural and urban management and planning, and cultural practices. Consequently, the impacts of heat waves can be reduced, and may in many places be manageable into the future, through implementation of such measures as public health warning systems, effective land management, penetration of air conditioning, and increased monitoring of vulnerable or exposed individuals. Given the potential for severe impacts of the more intense heat waves that are virtually certain to occur in the warmer future, it is critical that both the physical and social sciences be considered together to enable society to adapt to these conditions.
