In what sense do 10% of people die of the cold? And why is heat-related death most common in Greenland?

Scott Alexander in Astral Codex Ten:

People are most likely to die of extreme cold in Sub-Saharan Africa, and most likely to die of extreme heat in Greenland, Norway, and various very high mountains. You’re reading that right – the cold deaths are centered in the warmest areas, and vice versa.

This has got to all be wrong, right? 10% of Africans freezing to death, a substantial number of Greenlanders dying of the heat? The paper doesn’t have any answers. It just presents its mathematical model and runs away. So what’s going on?

More here.