The article seeks to expand our knowledge of which specific causes of morbidity are most affected by environmental temperature rises, an increasingly relevant aspect due to the effects of climate change. They use data on hospital admissions in Spain over an extended period of time (2006-2019).  

The study is limited, which is not attributable to the authors, by the availability of data on hospital admissions that the National Institute of Statistics allows, both in terms of territorial scope (as it is only accessible with provincial disaggregation) and in the identification of the persons admitted (as they are anonymised, they cannot know if a person is admitted on more than one occasion). For this object of study, it is very relevant, as has recently become clear in the new map for activating heat alerts in Spain, to take into account territorial groups that are smaller than the provinces. The authors have tried to minimise this deficit by analysing the association between an indicator of the degree of rurality/urbanity of the province and heat-related morbidity risks. On the other hand, it would also have been of interest to determine whether, within each specific cause of admission, people who are admitted more frequently are affected differently from those who are admitted more sporadically, something that the absolute anonymisation of the data prevented. 

The main contribution of the study is in providing evidence on the effects of high temperature on some causes of morbidity that, until now, had not been cited among those affected. And also in the analysis of other variables of interest such as atmospheric pollution, relative humidity or the duration in days of the rise in temperature, although its results limit the impact of these other variables to a small number of diseases. The study highlights, above all, the effects that high temperatures have on metabolic diseases and obesity and how, in these causes, the added effects of atmospheric pollution can be seen. 

These results, in addition to providing evidence on the morbidity affected by high temperatures, also serve as a basis for supporting, improving and pointing out the deficiencies in the availability of the data needed to be incorporated not only in the specific analysis, but also in the surveillance and early warning systems to reduce the negative effects on the health of the population.