France, Spain, the United Kingdom, Belgium, the Netherlands, Switzerland and Germany experienced record-breaking temperatures in late June. The national weather service, DWD, reported that Germany had never experienced such intense heat for so long so early in the year.
Now, large parts of the central and eastern United States are also under a heat warning over the July 4 holiday weekend, with temperatures expected to reach 100 to 115 degrees Fahrenheit (37.8-46.1 C) due to extreme heat across much of the region.
Such a heat wave, in which day temperatures remain above 30 °C (86 Fahrenheit) and night temperatures do not drop below 20 °C, exerts enormous stress on the human body. This is especially true for small children, pregnant women, older adults, people with underlying health conditions, and people who perform physically demanding tasks or work outside.
Are people in hot areas better able to cope with the heat?
“The human body can adapt, and these adaptations are more developed in people who are constantly exposed to heat,” said physician and university professor Claudia Traidl-Hoffmann. She is the director of the Institute for Environmental Medicine at the University of Augsburg, where she treats patients with environmentally related diseases.
Traudl-Hoffmann Helmholtz is also director of the Institute for Environmental Medicine in Munich, where she researches environmental diseases. As a member of the German government’s Scientific Advisory Council, she advises policy makers.
Adaptation to changing environmental conditions takes time, writes Traudl-Hoffmann in her book “Medicine of the Future – Healing in a Changing World” (original German title: “The Medicine of the Future – Healing in a Changing World”). But it is not a matter of years – it will take centuries.
What happens to the human body in summer?
“Once the external temperature reaches 23 C (73.4 F), the body begins to activate mechanisms to regulate its temperature,” Tradel-Hoffmann explains. The blood vessels dilate, which helps the body expel heat. Sweat provides additional cooling. Together, these processes help maintain a stable core body temperature.
If these mechanisms do not work properly or fail completely, the results can range from heart disease and stroke to multiple organ failure. The latter occurs when the body cannot maintain a stable core temperature.
“When our body temperature rises too high, metabolic processes initially accelerate further – until the body loses control – at all levels from the immune system to the nervous system. At about 42 degrees Celsius (107.6 F), the body experiences severe cell damage, multiple organ failure and, without immediate treatment, death can occur,” Treadle-Hoffmann said.
Lungs also suffer due to extreme heat. At the molecular level, the underlying processes are not yet fully understood, but there are several hypotheses, Traudl-Hoffman said. Breathing hot air appears to speed up the inflammatory process.
“The lungs become more easily inflamed and more susceptible to infection,” he said.
What should we do and what not to do during heat wave?
Traddle-Hoffman said people think about heat and its impacts only when temperatures have already risen – when rail tracks begin to bend, roads begin to crack and emergency services are stretched to their limits.
She advises her patients to be prepared for hot weather from the beginning of January. This includes discussing possible medication adjustments with your doctor. Because heat can intensify inflammatory processes, conditions such as allergies should be treated beforehand with specific immunotherapy, when appropriate.
Heat can also worsen eczema, making prompt treatment important. “Every chronic condition should be stabilized before the summer season begins,” the doctor said.
Once the thermometer starts to climb, Tradel-Hoffman recommends drinking plenty of water, eating a light plant-based diet, and avoiding cigarettes and alcohol whenever possible. Getting enough sleep at least gives the body a chance to recover from the heat stress of the day.
Can our bodies adapt to a warming climate?
Heat prevents many people from getting enough sleep, and the body is more likely to reach what doctors call decompensation, the point when it can no longer compensate for physical dysfunction.
How well the body can withstand and adapt to heat all depends on how exposed a person is. Traudl-Hoffman compares the body’s ability to adapt to a barrel: For older people, those with chronic diseases or taking medications, the barrel fills much faster during a heat wave.
Young, physically healthy people who are accustomed to hot weather generally have a greater tolerance, he said. But still, it also has its limitations.
“This rapid increase in the number of warm days, this rapid pace of change, is beyond the adaptation of ecosystems and humans,” he said.
This article was originally written in German.