Consistently applying agreed definitions of meteorological and climatological events can help develop a comprehensive understanding of a phenomena of interest. Extreme heat is a good example. The well-developed climatological understanding of extreme heat has been made possible, in part, by applying consistent methods and definitions. These include the ETCCDI indices (Zhang et al., 2011), to describe moderate extremes, Excess Heat Factor and the definitions outlined in Perkins and Alexander (2013), to describe heatwaves, and Extreme Value Theory to describe the very tails of the distribution (Wang et al., 2013).

Yet while the climate community has largely embraced the definitions outlined above (or some form of them), they have not necessarily been developed or applied with end users in mind. For example, what might be considered extreme climatologically may not be considered extreme from a human health perspective. It begs the question: are those dealing with the impacts of extreme heat receiving the climatological information they need?

Here we review and contrast the plethora of definitions and methods used to detect extreme heat with those used to examine the impacts of extreme heat globally. We decompose the latter (‘end users’) into three broad impact groups: human health; agriculture and biodiversity. We find that despite extreme heat being the most well understood product of climate change, the sector specific requirements of extreme heat information are not well known. This reflects the unique requirements of each end user and the complexity of the heat-impact relationship.

Our findings are pertinent for government who are charged with translating research into policies that aim to insulate impact groups from a warming climate.