Climate change is no longer just an environmental issue—it is becoming a public health emergency for the brain. Across Europe, rising temperatures, deteriorating air quality, and the northward spread of infectious diseases are compounding the strain on neurological health, according to experts gathered at the European Health Forum Gastein in Austria.
Neurological disorders—from migraines to dementia and Parkinson's disease—affect roughly one in three people at some point in their lives, estimates cited by neurologist Ulf Kallweit, co-chair of the environmental influences task force at the European Academy of Neurology. Combined with mental health conditions, these disorders carried an estimated global economic burden of €1.5 trillion in 2019.
“Everybody is somehow affected or knows somebody who is affected by a neurological disorder,” Kallweit told Euronews Health on the sidelines of the forum. As climate change drives temperatures higher, he warned, the situation could deteriorate further, worsening existing conditions and potentially increasing the risk of developing new ones.
Heat puts the brain under pressure
One of the clearest concerns is the link between high temperatures and stroke. The number of stroke cases rises when temperatures climb above 30°C, Kallweit said. He warned that heat-related strokes, which currently account for around 1% of all stroke cases, could represent 5 to 8% within the next 20 to 30 years.
Heat also disrupts sleep, which is critical for brain recovery. Tropical nights—when temperatures stay above 20°C overnight—make it harder for the body to cool down, interfering with deep sleep. “Everybody who experienced the last summer knows that sleep gets worse in these kind of heat nights,” Kallweit said. Prolonged sleep disruption can have serious consequences: “If you don't sleep well, not maybe one night, but for a longer time, there's a huge increase, let's say, for the risk of getting a stroke or also becoming demented.”
Rising temperatures are also shifting the geographical range of infectious diseases carried by ticks and mosquitoes. Lyme borreliosis, transmitted by infected ticks, can cause neurological complications. Malaria, meanwhile, remains a concern for southern Europe. “Malaria is still not fully on yet there, but maybe in five or 10 years it may also affect us in southern parts of Europe,” Kallweit said.
Where you live matters
The risks are not shared equally. Children, pregnant women, older people, and those with pre-existing health conditions are particularly vulnerable to extreme heat and environmental pressures. If they live in deprived neighbourhoods, their health risks rise further. Recent research has found that people living in socioeconomic deprivation have poorer indicators of brain health, including lower total brain volume and more signs of vascular damage.
“If you have heat and you cannot afford an AC, then you are more bothered,” Kallweit said. Access to healthy food, housing conditions, and the surrounding environment also shape health outcomes. Urban environments are especially important: noise, pollution, and stressful living conditions can all affect wellbeing, while access to green spaces may offer some protection.
Improving access to green spaces is one potential way to support brain health. “Going out to the forest one hour per week decreases your stroke risk by 3% or dementia risk by 4%,” Kallweit said. He urged people to spend time in green surroundings and to protect their sleep by limiting exposure to light, noise, and other disturbances.
But individual measures are only part of the answer. Public policy can determine whether people have access to cooler homes, quieter neighbourhoods, and cleaner air. Kallweit called for safeguards against pollution and toxic substances, as well as changes to building design. “How buildings are constructed should be reconsidered because they're still looking very much to the south, where the sun is entering,” he said, adding that such architecture “may be changed in the future.”
The challenge is not inevitable. Policymakers can limit the risks through measures that reduce exposure to heat and pollution and improve the environments in which people live. As Europe grapples with the health impacts of climate change, the message from Gastein is clear: protecting brain health must become a priority in climate adaptation strategies. For more on how Europe is responding to climate and health challenges, see the Brussels climate march and COP31's climate finance gaps.
