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Catalonia: New Study Confirms Increased Risk of Cardiovascular Events During Cold Weather

October 13, 2017

By Paul Homewood


This study was published a few months ago, which looked at the effects of extreme temperatures on cardiovascular hospitalisations in Catalonia. (My bold)




Cold spells and heatwaves increase mortality. However little is known about the effect of heatwaves or cold spells on cardiovascular morbidity. This study aims to assess the effect of cold spells and heatwaves on cardiovascular diseases in a Mediterranean region (Catalonia, Southern Europe).


We conducted a population-based retrospective study. Data were obtained from the System for the Development of Research in Primary Care and from the Catalan Meteorological Service. The outcome was first emergency hospitalizations due to coronary heart disease, stroke, or heart failure. Exposures were: cold spells; cold spells and 3 or 7 subsequent days; and heatwaves. Incidence rate ratios (IRR) and 95% confidence intervals were calculated using the self-controlled case series method. We accounted for age, time trends, and air pollutants; results were shown by age groups, gender or cardiovascular event type.


There were 22,611 cardiovascular hospitalizations in winter and 17,017 in summer between 2006 and 2013. The overall incidence of cardiovascular hospitalizations significantly increased during cold spells (IRR = 1.120; CI 95%: 1.10–1.30) and the effect was even stronger in the 7 days subsequent to the cold spell (IRR = 1.29; CI 95%: 1.22–1.36). Conversely, cardiovascular hospitalizations did not increase during heatwaves, neither in the overall nor in the stratified analysis.


Cold spells but not heatwaves, increased the incidence of emergency cardiovascular hospitalizations in Catalonia. The effect of cold spells was greater when including the 7 subsequent days. Such knowledge might be useful to develop strategies to reduce the impact of extreme temperature episodes on human health.


This adds to already plentiful evidence that it is cold that kills, not heat.

What makes it particularly significant is that Catalonia has a relatively warm climate.

  1. Bloke down the pub permalink
    October 13, 2017 10:01 am

    This adds to already plentiful evidence that it is cold that kills, not heat.

    What makes it particularly significant is that Catalonia has a relatively warm climate.

    I’m sure I’ve seen elsewhere in your pages, that it’s areas that are normally warm that suffer the most from cold spells and areas that are normally cold that suffer the most from heatwaves. Acclimatization means that it’s the difference to the norm which is the issue, not the absolute temps.

    • Tim Hammond permalink
      October 13, 2017 10:31 am

      Yes, the supposed deadly heatwave in France in 2003 was nowhere near as hot or as prolonged as usual summers in many countries. And the fact that everybody went on holiday and left the old and the vulnerable in stuffy conditions didn’t help either.

  2. October 13, 2017 10:03 am

    Similar news from Antarctica, the BBC Wild Service was forced to give the explanation for the penguin deaths: unusually extensive sea ice:

    • Sheri permalink
      October 13, 2017 1:15 pm

      Oh, I bet that hurt!

      I see they haven’t given up trying to direct evolution no matter what change occurs—we need “more protections”. Why bother to teach natural selection when human beings refuse to let it happen? Maybe they don’t teach it anymore—just that humans cause everything?

  3. Tim Hammond permalink
    October 13, 2017 10:32 am

    As relevant is the fact that air pollution is worse in winter than in summer. The statistical deaths attributed to pollution are not controlled for the effects of underlying weather on mortality and morbidity.

  4. NandieD permalink
    October 13, 2017 11:31 am

    Yes, the article goes back a few months ago but was the first blog to bring the study to the attention of the sceptic community; then; and then

    You do realize your article’s title is word-for-word the same as the two latter blogs without citation? By a simple review, climatedepot cites the blog as the original source for that title. links to as the study’s original source in the blogger community.

    • October 13, 2017 9:06 pm

      Yes, it’s Climate Depot where I spotted it!

      But I always try to quote the original paper, rather than a twice removed reference

  5. October 13, 2017 1:52 pm

    Reblogged this on Climate Collections.

    • dave permalink
      October 13, 2017 3:29 pm


      Your headline is a little misleading. They did not study the effect of cold and heat per se but of cold-spells in the middle of winter and heat-waves in high summer.

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