Some napkin math. AC roughly halves the extreme heat mortality rate for users. If France (~25%) achieves the air conditioning penetration of Canada (~65%), 40% of the population will achieve half the deaths, down 20%. So installing a Canadian level of AC in France could prevent on the order of (1k * 20%) 200 additional deaths.
France has ~30M households, so to get to Canadian levels they'd need an additional 12M installations. At €3k per installation that's €36B, or ~€180M per life saved.
