Heat waves and extreme temperatures have become more frequent and intense in recent years due, according to scientists, to current global warming or they would be one of the ways in which such warming would manifest itself at the meteorological level, that is in the short term.
Often, but not always, the most intense heatwaves are preceded by another mini heatwave, lasting a few days, which acts as an anticipation to the second. Like severe cold waves, severe heat waves pose a health risk, particularly to the elderly and children and people suffering from chronic diseases.
In Europe, these summer heatwaves are generally linked to the latitudinal displacements of the African subtropical anticyclone which normally resides in subtropical latitudes, while in other areas of the world it is always the subtropical anticyclones that determine the heatwaves with their displacements.
Regarding health, extreme high temperatures have correlations with cardiovascular problems. The study Extreme temperature exposure and acute myocardial infarction: Elevated risk within hours? published on the Environmental research, explained: "Day-to-day change in ambient temperature is associated with acute myocardial infarction (AMI) attacks, but evidence is scarce about the effects of extreme temperatures on the risk of AMI within hours of exposure.
study investigated the hour-level associations between extreme temperatures and AMI occurrence. State-wide data on AMI patients and temperature during winter and summer of 2013-2015 were obtained for Queensland state of Australia.
We employed a fixed time-stratified case-crossover analysis to quantify the risk of AMI associated with temperature within 24 h after exposure. Subgroups analyzes by age, gender and disease history were also conducted. We observed a very acute effect of cold on men (occurred 9-10 h after exposure), women ( 19-22 h after exposure), and the elderly (4-20 h after exposure).
Cold was associated with elevated AMI risk for men within 9 h (OR = 2.1, 95% CI: 1.2-3.6), women within 19 h (OR = 2.5.95 % CI: 1.0-6.0), and the elderly within 4 h (OR: 2.0, 95% CI: 1.0-4.0). However, elevated risk of AMI associated with heat occurred 15 h later for men (OR: 3.9; 95% CI: 1.1-13.9) and 23 h later for adults (OR: 4.1, 95% CI: 1.1-15.4).
People never suffered AMI and the elderly with diabetes or hyperlipidaemia were particularly vulnerable to cold. Those that were particularly vulnerable to heat were men never experienced AMI or having hypertension or having hyperlipidaemia as well as women ever suffered AMI. Effects of temperature on AMI risk at sub-daily timescales should be considered to prevent cardiac events."