What CDC found
….a cold-related death might not be a direct death, while virtually all heat-related deaths are. So if we try to compare apples to apples….i.e. direct cold and heat-related deaths, we have found that heat-related deaths exceed cold-related deaths.The problem is defining a cold-related death. We know that, in winter, general mortality is often 10-15 percent higher than in summer during typical daily periods. Are these considered cold-related deaths? They are happening during the cold season, but are not directly related to cold. If you use this definition of cold-related deaths, then yes, cold would exceed heat-related.So in summary, it is all dependent upon definition, in my opinion. Comparing apples to apples, which would be to evaluate acute or short-term responses to weather, I would always give the nod to heat-related deaths. However, if you are considering the seasonal differences in daily mortality, rather than just the “spikes” that we find with acute deaths, I can see why one can argue that winter (or cold-related) mortality is greater.
Depending on the compilation nature of the dataset, the numbers of heat- or cold-related mortality are quite divergent. Consequently, in general, these separate mortality datasets should not be combined or compared in policy determination, and the specific dataset used in a given study should be clearly identified. All of the datasets suffer from some major limitations, such as the potential incompleteness of source information, long compilation time, limited quality control, and subjective determination of the direct versus indirect cause of death. These factors must be considered if the data are used in policy determination or resource allocation.