High Temps Aren't Just Bad For the Earth—They Affect Your Brain Too

It seems climate change is here to stay (RIP planet earth) which means summers will keep getting hotter and hotter. When temperatures reach 'fry an egg on your driveway' levels, it can be hard to think about anything else.

You can try to distract yourself, but the overwhelming heat will probably still occupy your mind and lead to numerous psychological challenges. You may just feel sluggish or irritable or you might have a more serious exacerbation of an underlying mental health condition.

“Extreme heat is a stressor both on the body and the mind,” says JoAnna Leuck, MD, Associate Dean for Academic Affairs at Burnett School of Medicine at Texas Christian University. “Individuals with mental health issues can have more extreme reactions to stress, which can cause their symptoms to worsen.”

Our body and mind like to stay in balance, but heat can throw that balance off. Dr. Nathan Carroll, Chief Resident Psychiatrist, Jersey Shore University Medical Center, observes, “As we feel the physical effects of heat, it can take a toll on our mental state. For example, a person feeling the effects of extreme heat might not be sleeping as well, so along with being fatigued, they may feel more irritable, angry, or anxious during the day.”

In this article, we’ll take you through some of the consequences of extreme heat on your brain and mental health, including its potential impact on mood disorders, cognitive function, and brain health. We’ll also share strategies for coping with extreme heat.

The Relationship Between Heat and Mental Health

Sandra Kushnir, Licensed Marriage and Family Therapist and CEO of Meridian Counseling, shares this story about heat and mental health: “One of my patients, who has been managing anxiety, noticed a significant increase in symptoms during a particularly hot summer. The constant discomfort from the heat made it difficult for them to sleep, leading to heightened anxiety and irritability. Through our sessions, we developed a plan that included staying hydrated, taking cool showers, and creating a cooler living environment. These strategies helped them manage their anxiety more effectively during the heatwave.”

In fact, research has shown a connection between heat and mental health. For example, a review of published studies on heat waves and mental health outcomes found that high temperatures were associated with a range of mental health impacts. The most evidence was found for increased suicide risk, however in extreme heat there was also evidence of increased emergency department visits and hospitalizations for a variety of mental health conditions.

Furthermore, another study found that in extreme heat, the increase in mental health issues could at least partially be due to decreased environmental awareness and decreased capacity for the adoption of behavioral change in conditions such as psychosis and schizophrenia. In addition, mental health issues are often exacerbated by certain psychiatric medications' capacity to increase heat vulnerability.

The extreme heat can have a substantial influence on mood, cognition, and behavior. “With extreme heat, there is… an increase in interpersonal conflict and violence,” says Leuck. “It can lead to mood changes, including anger and outbursts.”

Cheryl Groskopf, Licensed Marriage and Family Therapist in Los Angeles observes, “Neuroimaging studies have shown that extreme heat exposure can alter brain activity and connectivity, impacting cognitive functions like memory and attention. Your behavior might change too—you may snap at people more easily or have trouble completing tasks.”

This can be due in part to heat’s impact on neurotransmitters, which are the chemicals that help your brain cells communicate. The neurotransmitters serotonin, dopamine and norepinephrine are thought to be involved in thermoregulation, and these are the very neurotransmitters that many psychotropic drugs such as antidepressants and antipsychotics target. In addition, “heat can increase the release of [the stress hormone] cortisol, which can impact anxiety and mood,” Groskopf says.

Heat and Mood Disorders

Heat can make symptoms of several mood disorders, like depression and bipolar disorder, worse. “For individuals with depression, the additional stress and discomfort from heat can deepen feelings of hopelessness and fatigue,” explains Kushnir. “Those with bipolar disorder might experience more intense manic or depressive episodes. The physiological strain of maintaining body temperature can lead to sleep disturbances, which further destabilizes mood.”

Other conditions can be impacted by extreme heat too. For example, Groskopf observes, “the embarrassment of being excessively hot or sweaty can amplify social anxiety and feeling self-conscious.”

Heat and Cognitive Function

In the face of extreme heat, " there is not as much ability for certain cognitive functions, and one may have decreased memory, slower decision making, and decreased ability to pay attention to tasks,” says Leuck.

“Studies have shown that test scores and work productivity can decline significantly in hot environments," explains Kushnir.

Heat and Brain Health

Brain health can suffer when the body is exposed to extreme heat for a long time, too. As Groskopf says, “There is some evidence that exposure to heat-stress can cause inflammation, which can even damage certain brain cells. Over time, this may lead to problems with memory, learning, and overall brain function.”

In addition, Kushnir observes, “In certain conditions such as heat stroke where the body can not regulate its internal temperature in the face of extreme heat, the blood-brain barrier [a protective layer of cells that defend your brain from types of damaging substances] is disrupted, potentially leading to neurological issues.”

Coping Strategies for Extreme Heat

There are several things you can do to cope with extreme heat.

• Stay hydrated. Drink a lot of water and, as Carroll says, “Check up on family members who may forget to drink fluids.”
• Wear light, breathable clothing and try to stay in shaded or indoor spaces, especially during the hottest times of the day. “Go to public spaces with air conditioning,” says Carroll, “such as libraries, malls, and shopping centers, if you don’t have [air conditioning]….”
• Use a portable fan, if possible. “I once brought a mini portable fan to a friend’s wedding in the blazing summer heat,” says Groskepf. “Within an hour, there was a line of friends waiting to cool off with it. This small step made a huge difference and kept me more comfortable.”
• Practice relaxation techniques, such as mindfulness and deep breathing. As Kushnir explains, "[relaxation techniques] can reduce stress and improve mood."
• Talk to your doctor about any psychiatric medications you’re on that may make you more sensitive to heat. Carroll explains, “Antidepressants, antipsychotics, and benzodiazepines can decrease our thirst sensations (so we can't tell we're getting dehydrated) [and] antipsychotics and anticholinergic medications can affect our internal thermoregulation. Lithium, a common medication for bipolar disorder, in particular, can increase the risk for dehydration, leading to a potentially toxic increase in its own blood level.”

Keep in Mind

While the effects of extreme heat can be difficult to handle, especially if you have a mental health condition, it can be done.

For example, Carroll tells this story: “One of my patients loves gardening, walking, and hiking. However, they are very sensitive to heat, were getting lightheaded during [a] heatwave, and are taking medications that are known to cause dehydration. We discussed staying hydrated, getting out of the midday heat, and getting into the shade. We also discussed changing their summer routine to avoid the worst effects of the heat.”

It can be difficult to change your routine, especially if it impacts what you can do, but in heat waves, it may be best to adjust things for the benefit of your mood, brain, and mental health.