A particular focus since AR5 has been the impact of climate change on cities . Heat risks are expected to be greater in urban areas due to changes in regional heat exacerbated by 'heat island' effects  , with intra-urban scale variations in heat exposure attributable to land cover contrasts and urban form and function . However, further research is required to establish the health implications of increasing chronic slow-onset extreme heat  in addition to the acute health outcomes of UHI-heatwave synergies under climate change. The latter is particularly important as studies that address UHI-heatwave interactions have mainly focused on changes in UHI intensity ; Scott et al. ). Whether significant urban mortality anomalies arise from the interplay of heatwaves and UHIs largely remains an open question although at least one study demonstrated higher urban compared to rural mortality rates during heatwaves . The benefits of the winter UHI effect for cold-related mortality remain largely unexplored, but one study for Birmingham, UK, indicates the winter UHI will continue to have a protective effect in future climate .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report