Masselot et al. looked a mortality records in 854 urban areas in Europe over a 20-year period (2000-2019). They found 20K deaths attributable to heat and 204K deaths attributable to cold, a factor of 10 larger.
Excess mortality attributed to heat and cold: a health impact assessment study in 854 cities in Europe
https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(23)00023-2/fulltext
DB2