The risk ratio, calculated as the ratio of the Cumulative Density Functions (CDFs) between the historical and projected simulations, of the cold (a,c) and warm (b,d) tails, with (solid black line) or without (dashed lines) the projected kurtosis change (as done in Fig. 4j,k and Fig. 5j,k in the manuscript, but here for kurtosis changes rather than skewness changes), for east-central North America during winter (first row) and central Europe during summer (second row). This is achieved by reproducing the PDF distribution, keeping the mean, variance and skewness changes, but neglecting the kurtosis changes. Compared to the skewness, neglecting kurtosis changes leads to much smaller changes in the risk ratios associated with extreme warm and cold temperatures (even negligible for central Europe during summer).