2007, Piran, Slovenia

Universal Thermal Climate Index
minimum clothing insulation in the morning. These seasonal changes observed over the
second half of the last century in a representative set of Italian cites, associated with opposite
trends at different latitudes, emphasises the importance of clothing-related parameters. At
present this could be achieved by the integration of biometeorological procedures in weather
forecast systems, representing an important way to provide weather forecast information
useful for specific subjects. An example of this is provided by the Interdepartmental Centre of
Bioclimatology (CIBIC), in collaboration with Institute of Biometeorology (IBIMET), which
developed a daily automatic operational procedure to provide 72-hour forecast of
biometeorological maps specific for Tuscany and all Italy (Fig. 2).
(http://www.lamma.rete.toscana.it/bioclima/index.html)
DISCUSSION
This study emphasises the seasonal changes during the second half of the last century of the
outdoor minimum clothing insulation needed to maintain thermal neutrality in three important
and populous Italian cities located at different latitudes. For this reason, and because several
authors have reported geographical differences in the correlation of cold-related mortality and
outdoor clothing insulation values, more information should be included in daily forecasts
regarding optimal outdoor clothing that should be worn in different periods of the day during
each season, and in different geographical areas. This information could prevent individuals
from over- or under-dressing, in particular when the weather changes suddenly. Furthermore,
this is particularly important for people who spend most of their time in outdoor environments
(i.e. work activities which start early in the morning and continue throughout the day, in other
words the entire diurnal period), or for people defined at “higher risk”, such as specific
elderly subjects, or people affected by previous pathologies, especially cardio-respiratory
disease. In this study, the use of a thermal index applicable only in steady-state thermal
conditions, such as the PMV, does not represent a limit for general application purposes like
in regional or national planning. Of course, the thermal perception of the environment
assessed by using only these thermal indices represents a simplification, because intrinsic
factors like past experience, expectations, naturalness and time of exposure, may play
important role in the evaluation of thermal conditions. For this reason, attention has now
focussed on properly evaluating the outdoor thermal conditions, and an international team of
experts is now working to develop a sophisticated thermal index, the Universal Thermal
Climate Index (COST-730 UTCI). This could represent a further step towards improvement
of the automatic operative forecast procedure presented in this study.
ACKNOWLEDGEMENT
This study was supported by Tuscany Region “Servizio Sanitario Regionale” grant:
MeteoSalute Project and LaMMA TEST Project.
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