What was done
Daily mortality rates of people in Baden-Wurttemberg (10.5 million inhabitants) over the 30-year period 1958-1997 were analyzed to determine the sensitivity of the population of this moderate climatic zone of southwest Germany to long-and short-term episodes of heat and cold.

What was learned
With respect to long-term (seasonal) outside conditions of heat and cold, the authors say the mortality data "show a marked seasonal pattern with a minimum in summer and a maximum in winter."  With respect to short-term exposure to heat and cold, they found that "cold spells lead to excess mortality to a relatively small degree, which lasts for weeks," and that "the mortality increase during heat waves is more pronounced, but is followed by lower than average values in subsequent weeks."  The authors say this latter observation suggests that people who died from short-term exposure to heat possibly "would have died in the short term anyway."

With respect to this short-term mortality displacement in the case of heat-related deaths, we note that the authors' data demonstrate it is precisely that, i.e., merely a displacement of deaths and not an overall increase.  They found, for example, that the mean duration of above-normal mortality for the 51 heat episodes that occurred from 1968 to 1997 was10 days, with a mean increase in mortality of 3.9%, after which there was a mean decrease in mortality of 2.3% for 19 days.  Hence, the net effect of the two perturbations was an overall decrease in mortality of 0.2% over the full 29-day period.

What it means
In the case of both short- and long-term heat waves and cold spells, cold spells are clearly the more serious problem.  Hence, we could expect global warming to confer significant benefits upon mankind in both the short- and long-term; for in both situations, cold kills but heat heals, especially in the long-term, which is what global warming is all about.