Air-con and heat-stress deaths
I wish these complex matters were simpler - but they're not.
The first thing is the category - premature deaths. So many of those who die are already weakened - old or very young, or sick - and some of those would die in the relatively soon predictable future anyway.
Another feature is that again, some of those that die will be sick because they're poor - and therefore, not have access to air-conditioning.
That the human-race with access to air-conditioning is getting softer - not doubted.
That those well-fed humans with habituated access to air-con would be more prone to dying of heat-stress - probably a much rarer connection than existing infirmity of the old-age/young-age/underfed/existing illness suite.
Welcome to 'it ain't simple' (and please suspect anyone who says it is!)