Scientists unveil the impact of warm temperatures on cognitive abilities
In the sweltering heat of summer, it's not just our bodies that feel the strain. Our brains, too, are affected by the soaring temperatures, especially for those with neurological diseases and vulnerable groups.
Extreme heat can impair human brain function, leading to cognitive decline, increased anxiety, irritability, aggression, and worsened mental health conditions. This heat-induced impairment is particularly felt by children, the elderly, outdoor workers, and those with neurological diseases such as epilepsy and dementia.
The human brain rarely exceeds the body temperature by more than 1°C. However, when a person thinks, remembers something, or reacts to the surrounding world, the brain produces a significant amount of its own heat. Rising temperatures can stress the brain, causing confusion, disorientation, and agitation.
Neurologically, extreme heat causes the hypothalamus, the brain’s temperature regulation center, to prioritize cooling the body. This diversion of resources from the frontal lobe responsible for higher cognitive functions can lead to cognitive decline. Heat stress also stresses the limbic system, which regulates emotions, leading to restlessness and bad moods.
High nighttime temperatures can prevent people from sleeping normally, leading to a bad mood and the exacerbation of symptoms of some diseases. For each 10ºC rise in temperature, sleep duration drops by about 9.67 minutes. Poor sleep from heat leads to worsened mood, increased anxiety, irritability, and depressive symptoms due to altered brain function and emotional processing.
In people with neurological disorders, heat and dehydration can trigger or worsen neurological or behavioral symptoms, such as confusional syndrome. Some medications, including psychotropic and anticholinergic drugs, can increase vulnerability to heat-related cognitive and behavioral issues.
Heat waves also correlate with increased aggressive behaviors and higher rates of mental health crises requiring emergency care. In hot days, hospitalizations and mortality rates increase among people with dementia. For many people with epilepsy, poor sleep can increase the risk of seizures.
Simple precautions to protect brain health during extreme heat include staying well hydrated, avoiding heat exposure, and optimizing sleeping conditions to mitigate heat-induced sleep disruption. Given climate change’s role in increasing the frequency and severity of heatwaves, these effects underscore a pressing public health concern requiring further research and equitable climate policies.
Climate change is causing an increase in hot periods. June 2023 was the hottest on record, and this is just the beginning. The elderly regulate body temperature worse, making them more susceptible to heat-related health issues.
It's important to remember that extreme heat can have far-reaching effects, including on pregnancy outcomes. Professor Jane Hurst notes that there is a link between extreme heat and adverse pregnancy outcomes such as premature births.
Heat is linked to an increase in conditions like aggression and domestic violence. During abnormal heat waves, the number of domestic violence cases increases by 5%. Heat can worsen symptoms for people with dementia, and it's not uncommon for many people to wake up before their alarm in the summer, feeling irritated and exhausted due to high nighttime temperatures.
A rare neurological disorder, Drave syndrome, affects around 1 in 15,000 children. This disorder includes a form of epilepsy and is one of many neurological diseases that can worsen due to heat.
In one study, scientists found that out of 1000 deaths from ischemic stroke, two additional deaths occur on the hottest days. Extreme heat and humidity are linked to an increase in conditions like epilepsy, stroke, encephalitis, multiple sclerosis, migraines, etc.
As we navigate the rising temperatures brought about by climate change, it's crucial to prioritize brain health and take necessary precautions to protect ourselves and our loved ones from the harmful effects of extreme heat.
- Science shows that extreme heat can impair brain function, worsening neurological disorders such as epilepsy and dementia, and causing increased anxiety, cognitive decline, irritability, and aggression in vulnerable groups like children, the elderly, and outdoor workers.
- Environmental science reveals a connection between climate change and the increased frequency and severity of heatwaves, which has far-reaching impacts on health-and-wellness, including exacerbating symptoms of dementia and elevating hospitalization and mortality rates among dementia patients, as well as increasing the risk of seizures in people with epilepsy.
- In addition to affecting neurological disorders and mental health conditions, climate change also contributes to the rise in environmental issues such as water scarcity and air pollution, which can have negative outcomes for individuals suffering from chronic medical-conditions, causing further health concerns on multiple fronts.
