Complementing the longer-term changes in air quality arising from climate change are those associated with air pollution sensitive short- term meteorological events, such as heatwaves. Studies of individual heat events  and systematic reviews  provide evidence for synergistic effects of heat and air pollution. However, the health consequences of a possible additive effect of air pollutants during heatwave events were heterogeneous, varying by location and moderated by socioeconomic factors at the intra-urban scale . This, combined with the challenges associated with projecting future concentrations of health-relevant pollutants during heatwave events , makes it difficult to say with any certainty that synergistic effects of heat and poor air quality will result in a heatwave-air pollution health penalty under climate change.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report