Heat wave grips Germany: experts warn of severe health risks for vulnerable groups
As temperatures climb above 30 degrees Celsius over several days, doctors and researchers highlight the dangers especially for the elderly, children, and those with chronic illnesses.
The silent killer
Heat is often called a 'silent killer' because its death toll rarely appears directly in statistics. Instead, institutions like the Robert Koch Institute model excess mortality during heat waves. The RKI estimates that around 2,500 people died from heat in the past year. In hotter summers than 2025, that number was many times higher. Only a small fraction of these deaths are attributed to proven heat stroke; the most common recorded heat-related causes are cardiovascular and respiratory diseases, notes Veronika Huber of the Spanish National Research Council in Seville.
Only a small part of these deaths is traced back to proven heat strokes. The most frequently recorded heat-related causes of death are cardiovascular and respiratory diseases.
How heat stresses the body
When the mercury rises, the body works hard to maintain its core temperature around 37 degrees Celsius. Blood vessels dilate, lowering blood pressure, and the heart must pump faster and harder. This raises the risk of heart attacks, arrhythmias, and heart failure in people with pre-existing conditions. Sweating can lead to dehydration, which may cause circulatory collapse or thrombosis. Alexandra Schneider, an epidemiologist at the Helmholtz Zentrum München, emphasizes that heat is one of the most significant environment-related health risks both in Germany and worldwide.
Overall, heat is now one of the most important environment-related health risks in Germany and worldwide, alongside air pollutants.
Who is most at risk
Older people are especially vulnerable because their heat adaptation and thirst sensation are often impaired. Those with chronic conditions of the heart, kidneys, lungs, diabetes, or neurological diseases like dementia face heightened danger. Babies and young children are also at risk due to developing bodies, more time outdoors, and higher breathing rates, explains Marie Standl from Helmholtz Zentrum München. Pregnant women experience additional strain because heat can alter blood flow to the uterus and influence the course of pregnancy, says Petra Arck of the University Hospital Hamburg-Eppendorf.
Children are at risk because their bodies are still developing, they spend more time outdoors, are relatively more physically active, and have a higher breathing rate than adults.
Living conditions and other factors
Geriatric researcher Kilian Rapp from Robert Bosch Hospital Stuttgart points out that simple measures like moving to a cooler room or drinking more are impossible for people who are bedridden or have dementia. Living alone or on higher floors further increases danger. Rapp adds that the observed excess mortality during heat waves is almost exclusively due to older and frail individuals.
Persons who are bedridden or have dementia are no longer capable of such elementary measures.
Neurologist Ameli Breuer of Berlin Charité warns that many conditions worsen in the heat, including higher risks of stroke, migraine, and symptom deterioration in multiple sclerosis, epilepsy, and dementia.
