Table 1.

Key concepts and definitions in heat exposure studies aligned with the Intergovernmental Panel on Climate Change (IPCC) framework

Concept	Description
Exposure	The presence of people, livelihoods, species or ecosystems, environmental functions, services, resources, infrastructure, or economic, social, or cultural assets in places that heat could adversely affect.
Vulnerability	The propensity or predisposition to be adversely affected encompasses various concepts and elements, including sensitivity or susceptibility to harm and lack of capacity to cope and adapt to heat.
Hazard	The potential occurrence of a natural or human-induced physical event or trend that may cause loss of life, injury or other health impacts, as well as damage and loss to property, infrastructure, livelihoods, service provision, ecosystems and environmental resources.
Adaptive Capacity	The ability of a population to adjust to heat is linked to socioeconomic factors, resource access, institutional support and social determinants of health and is often diminished in urban poor due to limited access to cooling resources and health services.
Risk	There is a potential for adverse consequences when hazards interact with vulnerable and exposed elements. It is often represented as the probability of occurrence of hazardous events or trends multiplied by the impacts if these events or trends occur. Risk results from the interaction of vulnerability, exposure and hazard. In the context of heat, it refers to the likelihood and severity of negative outcomes due to heat exposure, considering the vulnerability and adaptive capacity of the affected population or system.