Do sudden changes in weather affect health?

This momentary episode of falling temperatures will hardly mean a truce, a pause in a trend in which, according to forecasts, periods of intense heat will increase in frequency and intensity, directly impacting well-being. Climate change is already negatively influencing the health of many people, especially the most vulnerable, whose bodies are less adapted to changes in temperature.

The data is clear. In the summer of 2022, the hottest summer in Europe on record, there were 61,672 premature deaths attributable to heat on the continent, according to a study conducted by ISGlobal and published last July in the scientific journal Nature Medicine.

In absolute terms, the country with the highest number of deaths attributable to heat throughout the entire summer of 2022 was Italy, with a total of 18,010 deaths, followed by Spain (with 11,324 deaths) and Germany (with 8,173).

Different epidemiological studies have shown that extremely high temperatures directly affect mortality, mainly due to cardiovascular and respiratory diseases.

A very high temperature can cause an insufficient physiological response of the thermoregulatory system, as well as a loss of water and electrolytes, which affects the functioning of different organs.

Generally, a healthy person can tolerate a variation in their internal temperature of approximately 3ºC without altering their physical and mental conditions, but exposure to excessive temperatures can cause serious health problems, especially in vulnerable individuals.. In addition to dehydration, sunstroke, cramps or decompensation, heat stroke is one of the main risks, since it can cause multi-organ problems, seizures and even coma.

The people most vulnerable to heat stroke are “the elderly, children, dependent people and those who have chronic pathologies or take medication,” explains Guadalupe Fontán, coordinator of the Research Institute of the General Nursing Council, who details that the symptoms of the disorder are “redness of the skin, headache, confusion, dizziness, nausea, and even loss of consciousness.”

Since 2004, there has been a National Preventive Action Plan in Spain for the Effects of Excess Temperatures on Health, whose objective is to reduce the potential effects associated with high temperatures during the summer.

Among other measures, the plan sets temperature thresholds for each province and warning signs that indicate the risk of excess mortality associated with high temperatures.

According to the Ministry of Health, the risk of mortality attributable to high temperatures grows, with a probability of 95%, between 9.1% and 10.7% for each degree that the ambient temperature is above the threshold established for each province. In Asturias, this threshold is set at 26ºC while in Córdoba this figure is 41.5ºC, since different factors are taken into account in addition to what the thermometer shows.

For Jaime Martínez-Urtaza, a researcher at the Department of Genetics and Microbiology at the Autonomous University of Barcelona (UAB), it is important to bear in mind that this expected drop in temperatures “is punctual because temperatures rise again over the weekend”. .

This oscillation of temperatures does not pose any risk to health, explains. “The temperature drop is going to be something like temperatures returning to very reasonable levels. I do not believe that a similar situation generates notable health problems, when it is also a question of moving from extreme temperatures to a more 'livable' range,” he points out.

What does seem to be clear is that “for the first time we are feeling that we are entering a new phase, that we have already reached a new situation of no return where everything begins to unravel a bit. And this coincides with El Niño, pumping out heat and humidity, making everything even more noticeable,” he says.. And he concludes: “The combination of heat and humidity is even worse than high temperatures alone, since it makes the environment unbreathable and triggers many of the pathogen vector cycles.”