The human ecology of climate change - Climate Change: Biological and Human Aspects - page 397

That excess mortality in heatwaves, or cold spells, is dominated by what a popula-
tion is used to, and how it copes, as well as physiological acclimatisation rather than
intrinsic physiological failings, was highlighted by a study that compared summer
mortality in a hot part of Europe (Athens, Greece), a median part of Europe (London,
Britain) and a cool part of Europe (north Finland). Heat-related mortality occurs at
higher temperatures in hotter regions than in colder regions of Europe but does not
account for significantly more deaths in hotter areas. Surveys indicate that people in
cold regions of Europe protect themselves better from cold stress at a given level of
outdoor cold. A similar explanation, better protection from heat stress in hot than
cold regions, also helps account for these findings (Keatinge et al., 2000).
Of the possibly avoidable deaths from extreme heat or cold events, it is the excess
mortality above the norm in winter that can more easily be negated. Heating to combat
cold need not rely on advanced technology and basic heating technology is as old
as the camp fire. Conversely the least avoidable deaths will be those from excess
summer heat, because to negate this usually does involve the higher-level technology
of air conditioning. Before the use of air conditioning in the developed industrialised
countries, major heatwaves would typically increase mortality in cohorts over 50 by
several-fold. In 1936, one of the hottest summers on record in the USA, some 4700
people were estimated to have been killed directly by heat stroke. This represented
an increase of several per cent above the numbers of deaths expected over the same
period. Again, in Melbourne, Australia, in 1959, there was a 4-fold increase in
mortality (145 excess deaths) that was directly attributable to a prolonged heatwave,
although most of these occurred in the first 4 days of the event, for reasons presumably
akin to those where mortality from a successive run of bad winters occurs early in
the run (see above). A similar pattern of early-run mortality occurred during the run
of summer heatwaves in Los Angeles in 1939, 1955 and 1963 (McMichael, 1993).
At the end of the 20th century in the USA some 1000 died each year from extreme
cold events, but twice as many died from extreme warm events. This last might in all
probability be an underestimate, as a proportion of death certificates made out during
heatwaves cite respiratory disease or some other cause rather than heat stroke.
The UK provides an example of a policy response to the likelihood of increasing
heatwaves. The August 2003 heatwave in north-west Europe is estimated to have
caused some 15 000 extra deaths in France, 2000 in Spain, 1300 in Portugal and
around 2000 in England and Wales. In 2004, from concerns that climate change will
increase the frequency of heatwaves, the UK Government's Department of Health
and the National Health Service published a Heatwave Plan for England (National
Health Service, 2004). As outlined in the box, the plan has four levels of response
for when threshold temperatures are forecast or exceeded. This plan is to be further
developed over the years.
TheHeatwavePlanforEngland
The plan details a heat-health watch from the beginning of June to mid-September each year. It consists
of four levels of response based on threshold temperatures. These vary with region but are approximately
30 ◦ Cinthedaytimeandapproximately15 ◦ Catnight.