extreme heat

What happens to the brain during extreme heat: 5 fascinating facts

Fact 1. The brain overheats faster than the body.

In hot weather, the body begins working overtime to cool itself down: it sweats more, dilates blood vessels, and increases breathing rate. But the brain — which consumes up to 20% of the body’s total energy — overheats much faster. It’s highly sensitive to temperature changes, and even a slight rise in heat can affect its function. For example, imagine trying to work or solve an important task in a stuffy office without air conditioning. You try to focus, but everything irritates you, your thoughts are jumbled, and your head feels heavy. These are early signs that your brain is overheating. If you don’t take a break, drink water, or go outside for fresh air, this can escalate into heat stroke. That’s why during hot weather, it’s important to take frequent breaks, keep water close, avoid direct sunlight, and pay attention even to mild dizziness or fatigue — they could be early symptoms of brain overheating.

Fact 2. Emotional stability may decrease.

When its unbearably hot outside, many people notice they become more irritable, impatient, or prone to sudden anger for no clear reason. And it’s not just a subjective feeling — research confirms that high temperatures affect the functioning of the brain’s prefrontal cortex, which is responsible for self-control, rational thinking, and emotional regulation. For example, imagine someone standing in line in a stuffy store — every little thing, like the rustling of a bag or someone moving slowly, becomes much more irritating than it would in normal weather. In cities where temperatures frequently exceed 86°F (30°C), there’s a recorded increase in domestic conflicts during heatwaves. Emotional instability in the heat may also manifest as tearfulness, anxiety, or a feeling of exhaustion — even if there’s no objective reason for it.

Fact 3. Memory deteriorates.

When the air temperature rises to 86°F (30°C) and above, the body redirects its resources toward cooling itself rather than concentrating or memorizing information. As a result, the effectiveness of the hippocampus — the part of the brain responsible for memory and learning — decreases. People begin to forget simple things more often: what they were about to say, where they put their phone, or whether they locked the door. This shows up as “forgetfulness without reason” and can add extra stress, especially in important work situations. Additionally, dehydration, which often accompanies heat, further slows down the transmission of nerve impulses, worsening focus and the ability to absorb new information. A simple task that would normally take five minutes can turn into a real challenge in the heat. Therefore, on such days, it is especially important to plan complex tasks for the morning or evening hours, monitor your water balance and not demand a lot of productivity from yourself. This is not laziness, but a reasonable adaptation to the conditions in which the brain needs support.

Fact 4. Logical thinking becomes impaired.

Under extreme heat, the brain loses its ability to analyze information effectively and make rational decisions. When overheating, the body shifts into survival mode: activity in the cerebral cortex — responsible for planning, critical thinking, and impulse control — decreases. For example, a person may find it difficult to assess a work situation clearly, compare different options, or formulate a coherent response in a discussion. Where logic usually kicks in under normal conditions, heat often triggers emotional or impulsive reactions instead. This increases the risk of conflicts, flawed conclusions, or poorly thought-out decisions. This effect is especially noticeable during prolonged concentration: if you’re working with numbers, writing an analytical report, or preparing a presentation, the heat can significantly reduce the quality of your output. In such conditions, you should take frequent breaks, ensure regular ventilation of the room and drink enough water.

Fact 5. Anxiety may intensify in sensitive individuals.

When it’s very hot outside, the body experiences physical stress: the body overheats, the pulse speeds up, sleep is disturbed and the quality of breathing decreases. For people prone to anxiety, these changes can be subconsciously perceived as a threat. The brain responds instantly, triggering a wave of anxious thoughts, bodily tension, and emotional agitation. People may experience these symptoms especially acutely at night.  A person may feel like “something’s wrong” without realizing that heat is the actual trigger. This creates a vicious cycle: anxiety amplifies stress, and stress combined with heat further depletes the nervous system. Those who are prone to depressive or anxiety disorders should be especially careful, as symptoms can be exacerbated on hot days.  In such cases, it is advisable to consult a specialist who will help you choose individual support methods or, if necessary, prescribe medications (for example Aurorix, Ipca-Escitalopram, Depsol-25, Trazalon 50)  to improve your psycho-emotional state.