THURSDAY, July 27, 2023 (HealthDay News) -- While the record-breaking heat the United States is experiencing this summer can stress people to their limits, it can be particularly hard to navigate for those with mental health issues.

"All mental illnesses increase with heat because it results in more fatigue, irritability and anxiety, and it can exacerbate depressive episodes," said Dr. Asim Shah, executive vice chair in the Menninger Department of Psychiatry and Behavioral Sciences at Baylor College of Medicine in Houston.

Excessive heat can cause anger, irritability, aggression, discomfort, stress and fatigue. Heat acts on serotonin, the neurotransmitter that regulates mood, leading to lower levels of happiness and increased levels of stress and fatigue, Shah explained.

The most vulnerable groups include those with preexisting conditions and people who use abuse substances like alcohol. If people use substances, especially alcohol, they need to be more hydrated because combining substance use with heat requires even more hydration.

Heat can make mental health issues worse, including aggressive behavior and mental fogging. In the worst case, confusion and disorientation can occur.

What can someone with mental health issues do?

Shah recommends hydrating and keeping your head covered outside. Pour water on your head to cool down and try staying in shade. If you usually go for walks outside, move inside by walking in a mall or a large space with air conditioning.

If you take medications, consult your doctor before mixing your dose with excessive heat. Some medications for mental health, such as lithium, might not pair well with heat. Lithium goes through the kidneys, so if you sweat more, levels of the drug can fluctuate, Shah explained.

“If you are out in the heat and using lithium, levels may fluctuate. In that scenario, we have to be very careful and either adjust the dosage of lithium or avoid heat,” he said in a college news release.

Climate changes, like droughts and extreme changes in temperature, can also triggers rises in pollutants and allergens that worsen air quality.

"Children are a vulnerable population due to their physical and cognitive immaturity. They are exposed to more pollutants and allergens as they spend more time outdoors," Shah noted.

More information

The American Psychiatric Association has more on heat and mental health.

SOURCE: Baylor College of Medicine, news release, July 24, 2023