The Alarming Ways Extreme Heat Affects You Brain

With summer heat waves continuing to scorch much of the world, it’s not surprising to see and feel changes in behavior, for adults and children alike. This is because the brain has a very narrow range of optimal operating temperatures. When the brain becomes overheated, it can lead to many physiological and neurological changes that can impact cognitive function, consciousness and overall health. Unfortunately, most of these changes are associated with memory loss and decreased focus, and are expressed through behaviors such as increased irritability, aggressiveness, anxiety and feeling ‘brain fog’.

Changes in your brain temperature can be from internal sources (fever) or external (hot weather). But in either case, as your brain temperature increases, so, too, does negative behaviors. The Yale School of Medicine published a recent paper in the Journal of Neural Engineering that concluded even, “small increases in temperature while stimulating the brain can profoundly alter brain activity.” A 2021 study also found that as temperatures rise above 75 degrees Fahrenheit, changes in cognitive performance could be noted.

According to Caroline Leaf, PhD, a neuroscientist and mental health expert, “Short bursts of high heat exposure, like sitting in a sauna, are good for you and can even build up your resilience and improve your focus. However, longer periods of extreme heat are potentially problematic as the changes in brain chemistry can cause neurons to either fire too fast or too slowly, sometimes even going ‘silent’, which can impact how a person thinks, recalls, feels and sleeps. This, in turn, can make someone more tired, overwhelmed, aggressive, and irritable, and can further drains the energy from the brain and body, making us feel even worse.”

So what exactly happens to the brain when it’s overheated? Several interconnected things appear to happen at once.

• Neurotransmitter Imbalance: Neurotransmitters are chemicals that transmit signals between nerve cells. Overheating can disrupt the balance of neurotransmitters in the brain. An imbalance in neurotransmitters can affect mood, cognition and behavior, and can lead to symptoms such as confusion, irritability and difficulty concentrating.
• Electrolyte Imbalance: Overheating can cause the body to lose electrolytes through sweating. Electrolytes are essential for maintaining proper nerve function, muscle contraction and fluid balance. An electrolyte imbalance can result in muscle cramps, weakness, and in severe cases, even seizures.
• Impaired Cognitive Function: High temperatures can impair cognitive function and decision-making. Studies have shown that tasks requiring attention, memory and reasoning can be negatively affected when the brain is overheated. This can lead to decreased performance.
• Risk of Heat Stroke: In extreme cases, prolonged overheating can lead to heat stroke, a life-threatening condition. Heat stroke occurs when the body’s core temperature rises to dangerous levels, leading to confusion, loss of consciousness, seizures and even coma. Heat stroke can cause permanent brain damage if not treated promptly.
• Reduced Blood Oxygen Levels: Overheating can sometimes cause shallow and rapid breathing, which may result in reduced oxygen levels in the blood. Lower oxygen levels can impair brain function and contribute to feelings of confusion and disorientation.
• Inflammation: Elevated body temperature can trigger an inflammatory response in the body, including the brain. Inflammation in the brain can potentially contribute to neurological disorders and impact cognitive function.
• Increased Blood Flow: One of the initial responses to overheating is an increase in blood flow to the brain. This is the body’s attempt to cool down the brain and maintain its normal temperature. However, excessive blood flow can sometimes lead to swelling and increased pressure within the skull, potentially causing headaches, dizziness, and even fainting.
• Impact on Blood-Brain Barrier: The blood-brain barrier is a protective layer that regulates the passage of substances between the bloodstream and the brain. Overheating and inflammation can compromise the integrity of the blood-brain barrier, potentially allowing harmful substances to enter the brain and cause damage.

If you find yourself beginning to feel the effects of the current weather, it’s crucial to take immediate steps to cool down and avoid overheating. Here are a few ways to help lower our brain and body temperature:

• Stay Well Hydrated: Drinking plenty of water can help keep your body and brain in balance. Sucking on ice when you feel too warm can also help to hydrate and quickly cool the body.
• Stay In (or Seek) Cooler Environments: If it’s possible to stay home and keep the air in your space cool, do so. When that isn’t possible, seek to spend as much time in areas with cool temperatures as possible. This includes evenings and nighttime. Environments with fans and air conditioning are best.
• Take a Cold Shower or Ice Bath: Even one to three minutes in cool water can help bring your temperature down.
• Keep Children Well-Fed and Engaged: Children often need extra attention to prevent overheating. In addition to the above recommendations, it’s important to ensure kids ae getting the nutrients they need every day. That means feeding their bodies and their minds to help them navigate the stressors of heat. Indoor games and reading are great ways to keep them engaged, but cool.