ABSTRACT
Globally, thermal extremes present a major environmental hazard affecting human health, agriculture, energy, and economic systems. This chapter introduces the topic of heat- and cold-related hazards, providing a historical context of past and future events. Social dimensions of vulnerability draw attention to the array of interconnected factors that play a role in determining risks. Various populations experience heightened sensitivity to thermal hazards. Due to improvements in social, technological, and infrastructure factors, vulnerability to heat hazards has declined over time. Heat-health warning systems have been developed around the world and are designed to increase awareness of the impact of heat on human health. Despite progress, many populations such as outdoor workers, rural residents, and vulnerable communities in much of the developing world are significantly under-represented in research to date. Continued monitoring and improvement of both heat- and cold-related mitigation plans are necessary, particularly with projected changes in the frequency and magnitude of heat events due to anthropogenic climate change and an aging population in many parts of the world.
