In recent years, Greece has witnessed a dramatic transformation in its climate. Winters have grown noticeably shorter, almost retreating into the shadows, while summers have become unbearably long and increasingly intense. Days upon days of searing temperatures now resemble those of a high fever, and according to newly gathered data from the FAME Lab at the University of Thessaly, this trend is not only set to continue — it is expected to escalate.
The lab’s latest findings suggest that Greece is heading toward an alarmingly hot future. The data, which will be officially released in a forthcoming Bank of Greece report on climate change this autumn, show a clear rise in extreme heat. During the summer months, the number of very hot days (with temperatures ranging from 35°C to 39.9°C) and officially recognized heatwave days (above 40°C) has already doubled compared to the past.
But what lies ahead is even more concerning. In large urban centers such as Athens, where one or two heatwaves per year were the norm between 1971 and 2000, projections indicate that by 2050, residents could experience over ten each year. By the end of the century, that number may rise to between 15 and 20. Even in the most optimistic global warming scenarios, Greece’s average summer temperature is expected to rise by around 2°C by mid-century. In a high-emissions scenario, that increase could reach 3.5°C, particularly in the country’s inland regions.
These temperature shifts carry serious consequences. The summers of the future will not only be hotter, but defined by more frequent, longer, and more intense heatwaves — a development that threatens to put significant pressure on public health systems and individual well-being.
One of the most pressing concerns is the effect of long-term thermal stress on the human body. It’s not just heatwaves that pose a danger. Sustained high temperatures, even below the 40°C mark, can steadily undermine health. Studies show that when daily highs exceed 37°C for several days and nights remain warm — above 20°C, producing what are known as "tropical nights" — mortality rates and cardiovascular incidents rise sharply across the general population.
What’s particularly striking is that the risks extend well beyond traditionally vulnerable groups. Even healthy adults can experience heat-related illnesses. Prolonged exposure to high temperatures can lead to dehydration, fatigue, muscle cramps, and eventually heat exhaustion. If the body’s core temperature isn't brought down, these symptoms can escalate to heatstroke — a medical emergency that can be fatal. Heat also places a heavy burden on the heart and lungs, increasing heart rate, lowering blood pressure, and triggering fainting episodes, even in people with no pre-existing conditions.
For those who are chronically ill, the risks multiply. The elderly, for example, are significantly more susceptible to heat stress, due to the body’s diminishing ability to regulate temperature effectively with age. Chronic diseases only deepen this vulnerability. It's no coincidence that older adults make up the majority of fatalities during heatwaves. In the summer of 2022, across Europe, mortality among individuals over 80 years old was nearly eight times higher than among those aged 65 to 79 during extreme heat events.
Workers are another high-risk group. Those employed outdoors — in agriculture, construction, or road maintenance — or in overheated indoor environments like factories and commercial kitchens, face daily threats to their health and safety. Heat reduces concentration, physical performance, and increases the risk of accidents. Across the European Union, deaths related to heat stress in the workplace have risen by 40% in recent decades — a clear indicator that climate change is reshaping occupational hazards.
Pregnant women are also particularly vulnerable to extreme heat. Recent international research shows that the chances of preterm birth increase by 26% during prolonged heatwaves. High temperatures have been linked to complications such as stillbirth, congenital anomalies, and low birth weight.
People living with chronic conditions face a cascade of dangers. Cardiac patients are at risk of irregular heart rhythms and sudden blood pressure drops, as heat causes blood vessels to dilate and dehydration stresses the heart. Respiratory patients suffer from worsening symptoms due to poor air quality during heatwaves, which often bring higher levels of ozone and airborne particles. Kidney patients are vulnerable to acute damage from fluid loss. Meanwhile, some psychiatric medications can impair sweating and temperature regulation, raising the risk of heatstroke in individuals with mental health conditions.
