How Extreme Heat Messes with Your Brain and How to Stay Sharp

As scorching summer heat blankets the U.S., with warnings stretching across the East Coast and Midwest, it’s not just your body feeling the burn—your brain’s taking a hit, too. Extreme temperatures can fog up your mental clarity, crank up irritability, and even nudge you toward anxiety, according to Dr. Jace Reed, an emergency psychiatry expert at Cedars-Sinai Hospital.

Heat’s Hidden Toll on the Mind
High temperatures don’t just make you sweat; they can slow your thinking, dull your memory, and make decision-making feel like wading through molasses. Reed warns that if you’re struggling to recall a conversation or fumbling tasks, the heat might be cooking your cognitive functions. Worse, severe confusion could signal the onset of heatstroke—a medical emergency requiring immediate attention.

Thea Gallagher, a psychologist at NYU Langone Health, explains that overheating throws your body’s internal balance out of whack. This can disrupt sleep, sap your energy, and scatter your focus. The brain faces oxidative stress and inflammation, potentially harming neurons and raising risks for those with neurological conditions or stroke-prone individuals. Prolonged heatwaves can also amplify mood swings and, in extreme cases, spark aggressive behavior.

Vulnerable Minds in the Heat
People with mental health conditions—like depression, schizophrenia, or dementia—are especially at risk. Gallagher notes that some psychiatric medications, such as SSRIs, can mess with your body’s cooling system by curbing sweat or, paradoxically, causing excessive sweating. Either way, dehydration looms large, heightening the danger of overheating. Those with cognitive impairments might not even notice they’re overheating until it’s too late.

Protecting Your Brain in a Heatwave
To keep your mind sharp, prioritize hydration and avoid overexertion during peak heat. Seek shade or air-conditioned spaces, and don’t skimp on sleep—long summer days can be draining. Gallagher advises slowing down when possible, as the season’s bustle can wear you thin. If you’re on medications, consult your doctor about heat-related risks.