How do high temperatures affect the brain? Experts offer tips to protect it.

Since August 3, Spain has been immersed in its second heat wave. Summer, as announced by the State Meteorological Agency (Aemet). Intense heat will be felt both day and night, reaching 42°C in several provinces in the south of the Iberian Peninsula, with lows not falling below 24°C and 25°C, especially on the Mediterranean coast and in the southern half. This situation is expected to continue until Sunday, August 10.

When the thermometer rises and temperatures exceed 38°C, the intense heat has a direct impact on people's health, affecting many bodily functions. In the case of the brain, the HM Hospital in Barcelona has warned that high temperatures can affect both cognitive function and emotional regulation, causing changes in memory, mood, and behavior.

When this situation occurs, special attention must be paid to those who suffer from a pre-existing neurological illness or disorder, as this increases the likelihood of experiencing episodes of confusion, disorientation, or agitation.

How do high temperatures affect our brain?

Adequate exposure to ultraviolet rays helps synthesize vitamin D, in addition to generating serotonin in our brain, stimulating our central nervous system and improving our mood by making us feel happier and more relaxed.

However, this situation changes radically when temperatures rise and reach or exceed 38°C. In these cases, the heat affects the hypothalamus, a region of the brain that acts as a vital control center, regulating temperature, hunger, thirst, and sleep, in addition to influencing emotions and behavior.

Similarly, through sweat, breathing and circulation the body is responsible for maintaining a constant temperature around 36 or 37 degrees, but when it is forced to make a greater effort to achieve this goal, due to the high external temperature, it becomes saturated and destabilized, which can lead to changes in memory, mood and behavior, as well as altering sleep and the feeling of hunger.

According to the head of the Neuropsychology Department at HM Nou Delfos Hospital, Dr. María García Galant, in the face of high temperatures, the hypothalamus makes a greater effort to keep the body cool, so it seeks reinforcement from other areas of the body.

"When this phenomenon occurs, the hypothalamus focuses heavily on fulfilling its function of keeping the body cool and, if necessary, draws resources from the frontal lobe, the area that houses cognitive flexibility, attention, working memory, and reasoning, so general cognitive function also suffers ," the doctor explains.

For his part, García Galant warns that the limbic system is also affected by heat and alters our emotions. "Another area affected is the limbic system, where we find emotions. For this reason, extreme heat can generate restlessness, apathy, bad mood, and aggression. Furthermore, overstimulation of the hypothalamus also prevents us from falling asleep and resting normally ," he states.

The feeling of hunger is also directly related to heat, as the body enters a kind of "energy saving" mode, requiring less food to function. In response, the need to drink fluids increases to stay hydrated at all times.

Greater impact on people with neurological diseases

The consequences of high temperatures are even more pronounced in the brains of people with a pre-existing neurological disorder or illness, increasing episodes of disorientation, confusion, and agitation. This is especially true for patients diagnosed with epilepsy, dementia, or acquired brain damage.

Dr. María García emphasizes that the routine changes we often make during the summer can lead to the appearance of various neurological symptoms. “ Extreme heat, dehydration , and changes in routine Such as travel, interruption of therapies , or changes in the usual environment can act as a trigger for neurological or behavioral symptoms, such as confusional syndrome," he says.

Furthermore, the doctor states that some medications may also be directly related to the presence of neuronal alterations during days of high temperatures. "Certain pharmacological treatments, such as psychotropic or anticholinergic drugs, can increase vulnerability to heat stroke with cognitive, behavioral, or neurological manifestations ," explains García Galant.

In response to this, specialists from the Neuropsychology area of the HM Nou Delfos hospital recommend the population to adopt and Maintain routines as much as possible, avoiding sun exposure during the hottest hours of the day and ensuring proper hydration. They also recommend establishing cognitive stimulation routines that continue throughout the summer.