This study was based on over three million emergency department visits related to substance use disorders, anxiety disorders, and more, all associated with extreme heat.

Understanding the Research

An association was found between periods of extreme heat and increases in emergency room visits between 2010 and 2019 for mental health reasons such as substance use, anxiety, depression, and schizophrenia. Researchers also found that rates of emergency room visits were higher during periods of extreme heat for men compared to other genders, and were also higher in the Northeast, Midwest, and Northwest regions of the US. This research may be the largest and most comprehensive analysis of daily ambient temperature, as associated with emergency room visits for mental health among individuals across the US, which can be the most costly.

Some Groups Are Especially Vulnerable

Psychologist Shamin Ladhani, PsyD, says, “While we typically associate extreme heat with increased risk of medically compromised individuals, readers might not consider that the mentally ill are also at risk." Ladhani explains that this study helps to bring awareness to the fact that individuals with mental health concerns are especially vulnerable during periods of extreme heat. “Research on how this might disproportionately impact low-income or underserved individuals is needed,” she says.  Given the limited mental health services available in emergency rooms, Ladhani notes that psychiatry or a mental health service may be consulted but may not always be directly available, unfortunately. “Access to mental health care has been impacted by the pandemic,” she says. Ladhani explains that extreme heat may impact physical health and subsequently trigger a stress reaction. “Individuals that take psychiatric medications may be more at risk of developing a mental health crisis, as the side effects of those medications can cause dehydration which could render the medication less effective or result in other side effects,” she says. Since this research aligns with other studies in this area, Ladhani notes that it is a large study and was able to identify that particular parts of the US are more vulnerable as they are not as well adapted to heat as other areas. Ladhani highlights, “Unfortunately they were unable to break out the demographics of the men and women in the study by race, ethnicity or socioeconomic status and they primarily looked at individuals with commercial insurance and Medicare Advantage which would not apply to low income individuals or those without insurance.” Providers should educate their patients about increased risks of mental health exacerbation during times of extreme heat so that they are able to provide coping tools and strategies to avoid this, according to Ladhani. Individuals from underserved backgrounds are likely to be more at risk due to limited access to resources, and Ladhani details air conditioning, clean water supply, and distance from emergency care as tangible examples. Ladhani notes, “Providing patients with additional resources like numbers for hotlines, information about cooling centers, and proactively making sure that patients are involved in mental health treatment can help.” Teaching how mental health may decline in heat may empower people to monitor moods, manage sleep, and reach out if needed, according to Ladhani. “Providers can also encourage patients to check on other vulnerable individuals in their community during extreme heat,” she says. 

Impacts Beyond Just Climate Anxiety

Licensed clinical psychologist, and co-founder and director of the Center for Cognitive Behavioral Therapy and Mindfulness, Suraji Wagage, PhD, JD, says, “This study revealed an association between extremely hot weather and increased emergency visits for mental health.” Wagage explains that this research demonstrated that mental health reasons included substance use disorders, anxiety disorders, and mood disorders across a large sample of 2.2 million adults. The study’s authors theorized that heat may be an “external stressor” that contributes to disturbed sleep, irritability, and discomfort, which can exacerbate mental health conditions, according to Wagage. This finding underscores the importance of considering the impact of a variety of factors, including the weather on mental health, as Wagage notes the interconnections between physical and mental wellbeing. Wagage explains, “Physical discomfort can take a toll on mental health, even if the discomfort does not rise to the level of chronic pain that is recognized as potentially deleterious for psychological health.” While this study is correlational, not causational, Wagage notes the greater implication is that climate change extends beyond “climate anxiety” in terms of its impacts. “The mental health impacts of natural disasters become more frequent as climate change accelerates,” she says. Wagage explains, “As with other effects of climate change, individuals living in under-resourced communities worldwide, disproportionately BIPOC, will bear the brunt if excess heat worsens mental health.” As they are more likely to live in areas with extreme temperatures, Wagage notes that these groups are more likely to have weather-exposed jobs, such as in construction and agriculture, and live without air conditioning.