Cold Weather vs. Warm Weather: Which Kills More People?
Vasconcelos, J., Freire, E., Almendra, R., Silva, G.L. and Santana, P. 2013. The impact of winter cold weather on acute myocardial infarctions in Portugal. Environmental Pollution: 10.1016/j.envpol.2013.01.037.
In exploring this subject for themselves, Vasconcelos et al. studied the effect of a daily human-biometeorological index known as the Physiologically Equivalent Temperature or PET, which is based on the input parameters of air temperature, humidity, mean radiant temperature and wind speed, as employed by Burkart et al. (2011), Grigorieva and Matzarakis (2011) and Cohen et al. (2012), focusing their attention on Lisbon and Oporto Counties in Portugal over the period 2003-2007.
In discussing their findings, the five Portuguese researchers report there was "a linear relationship between daily mean PET, during winter, and the risk of myocardial infarction, after adjustment for confounding factors," thus confirming that "the thermal environment, during winter, is inversely associated with acute myocardial infarction morbidity in Portugal," where they observed "an increase of 2.2% of daily hospitalizations per degree fall of PET, during winter, for all ages."
In Portugal, as in many other countries where, in the words of Vasconcelos et al., low winter temperatures "are generally under-rated compared to high temperatures during summer periods," cold weather is demonstrated to be "an important environmental hazard" that is much more deadly than the heat of summer.
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