The health risks of climate change arise from the interactions of the hazards associated with a changing climate (e.g. increases in the frequency and intensity of extreme weather and climate events, such as drought), the communities exposed to those hazards, the susceptibility of communities to adverse health impacts when exposed, and the capacity to prepare for and cope with the hazard. However, there is a very limited understanding of how extreme weather and climate events could themselves be sources of vulnerability. Drought is used as an example of an extreme event that can simultaneously be a current hazard and can directly and indirectly influence future vulnerability. A better understanding of droughts and other extreme events as sources of vulnerability is needed, including (i) the patterns of risks and how these could change over time, (ii) the reasons for any changes, (iii) how these risks could affect human health and well-being, and (iv) the longer-term consequences of extreme events for vulnerability. This knowledge will become increasingly important for managing risks to health as the frequency and intensity of extreme weather and climate events increase with climate change.