It is important to note that the assessed studies typically take an observed epidemiological relationship and apply future temperature projections  to these relationships. Because the relationships between temperature and CVD deaths are influenced by both climatic and non-climatic factors , future projections are highly sensitive to assumptions about interactions between climate, population characteristics and adaptation pathways. Changes in air quality because of climate change are an additional important factor. For example, an assessment of future annual and seasonal excess mortality from short-term exposure to higher levels of ambient ozone in Chinese cities under RCP8.5 projected approximately 1,500 excess annual CVD deaths in 2050 . To the extent possible, the relationships reported above reflect changes derived from changes in heat exposure driven by climate change and not changes in population demographics or air pollution exposure.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report