It's not an apples to apples comparison. 80%+ of deaths because of heat in Europe are 65+ years old.
When you start handling that range you've to take into account that these people are going to die because of something, save a guy from heat here and that's an extra death because of cancer 4 years later.
Now I'm not saying it's a thing to be ignored, but be wary of playing quick and dirty with statistics.