(NEXSTAR) – When the summer heat and humidity climb to unbearable levels, meteorologists, school administrators and government officials often discuss ways to stay cool – but what about the impact on our mental health?

Heat records are being broken with regularity, and last year was no exception. During a brutal and deadly summer in 2023, July became the hottest month ever recorded with modern equipment.

“This July was not just warmer than any previous July – it was the warmest month in our record, which goes back to 1880,” said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, after the record fell. “The science is clear this isn’t normal. Alarming warming around the world is driven primarily by human-caused greenhouse gas emissions. And that rise in average temperatures is fueling dangerous extreme heat that people are experiencing here at home and worldwide.”

The human body is really sensitive to heat, Dr. Susan Albers, a psychologist with the Cleveland Clinic, told Nexstar, but a heatwave can also take a toll on the mind.

“Warm weather usually helps our mental health, but excessive heat does exactly the opposite,” Albers said. “What studies have shown is that when the heat goes up, people are more irritable, angry, they have a lot of discomfort, difficulty, sleeping, cognitive issues.”

Heat and our minds

Seasonal affective disorder (SAD) is usually tied to winter, but experts say there is a subset of people who experience major depression during the summer.

Kelly Rohan, PhD, a clinical psychologist at the University of Vermont who studies the seasonal phenomenon, told the American Psychological Association (APA) that summer SAD is “understudied” but appears to be linked to how some people experience heat and humidity.

“Some of the same neurotransmitters, like norepinephrine, dopamine, and serotonin, that are involved in mood regulation are also involved in thermoregulation,” Rohan said, “so maybe there is some dysfunction in one or more of those neurotransmitter systems that confers a risk of depression as well as the inability to tolerate heat and humidity.”

While less common than it in winter months, Rohan said those who suffer from SAD in the summer tend to report weight loss, diminished appetite and insomnia. This is the opposite of common winter-type SAD symptoms, which often include weight gain, food cravings and sleeping too much.

Summer-type SAD may have a behavioral or cognitive component as sufferers trying to avoid the heat isolate themselves at home for days or weeks.

Heat can affect mental health in a variety of ways, research shows.

A 2022 study found that on the hottest days of there year there was an 8% jump in mental-health crises that resulted in a visit to a hospital emergency department when compared to the coolest days. The conditions included substance use disorders, anxiety, stress, schizophrenia, delusions, self-harm and childhood-onset behavioral disorders.

Researchers found that there were higher rates in the Northwest, Northeast and Midwest, possible because homes in those regions were less likely to have air conditioning than other areas, such as the South.

The importance of staying cool

When it comes to the connection between mood and the weather, Dr. Albers recommends a number of self-care measures people should take.

Whenever possible, do an errands or outdoor chores before 10 and remain indoors during the hottest part of the day.

“I also tell my clients to take cold showers, take a cold washcloth, put it on your forehead or behind your neck, and this is going to help you to cool off really instantly, and helps with some of those cognitive factors that go along with excessive heat,” Albers said.

Experts say nearly all psychotropic medications, with the exception of benzodiazepines, can further lower the body’s defenses against heat, elevating the possibility of heat exhaustion and heat stroke, according to the American Psychological Association.

It’s also important to pay attention to children, as they can get overheated easily, leading to tantrums and frustration which parents may just assume is bad behavior.

“Heat impacts neurotransmitter production, our sleep and the the quality of our hormone regulation,” Albers said. So those three factors are significantly impacting our mood, and the interplay between those two things can make or break our mood. In the short term, we can manage the symptoms of heat, day to day, staying inside, being cool.”

People who are already struggling with aspects of their mental health may be especially vulnerable during a protracted heat wave, and Albers says that is the best time to check in on the people in on loved ones.

“Some red flags that you are really struggling emotionally are changes in your daily functioning,” Albers told Nexstar. “You’re having difficulty getting to work, changes in appetite, your sleep. Those are some primary red flags, and it’s time to check in with your mental health provider or physician.”