As record-breaking heat has left the South and Southwest unbearable and unhealthy for any outdoor activity, millions of Americans have been forced to stay indoors and seek out air-conditioned places.
Psychiatric experts warn that the limits placed on people's activities will result in a major mental health emergency: summer seasonal affective disorder or SAD, which is atype of depression related to the weather, according to the Mayo Clinic.
Dr. Paul Desan, an associate professor of psychiatry at the Yale School of Medicine, told ABC News that the hotter temperatures, combined with the disruption of a normal summer routine could make more people more depressed, agitated and in need of professional counseling.
Desan, who is the director of the school's winter depression research clinic, said that the psychiatric community has limited data and research into the issue but they're already sounding the alarm as climate change will make more people susceptible.
"There's no question that higher temperatures produce more psychological distress and that distress has consequences," he told ABC News.
What is SAD?
Seasonal affective disorder was first identified by psychiatric researchers in the 80s.
The majority of SAD cases that have been researched were reported in the winter when the days are shorter. Winter symptoms are associated with lethargy and a lack of energy, brought upon by decreased daylight.
"We usually prescribe light therapy where we have a patient look at a bright light machine for about 30 minutes in the morning," Desan said. "That usually helps for the winter seasonal affective disorder."
Roughly 5% of American adults experience seasonal affective disorder and it typically lasts about 40% of the year, according to the American Psychiatric Association. Desean said research has indicated that winter SAD was more common in people who live farther from the equator, and estimated that it affected 1% of people in Florida and 9% of people in Alaska.
Dr. Yalda Safai, a psychiatrist and ABC News contributor, said when it comes to summer SAD, the data isn't as strong as there have been far fewer reported cases.
However, Safai said that according to what is known about the summer version of the condition is that it brings about different symptoms than its winter counterpart.
Depression in the forms of agitation, aggression and more irritability are seen in patients who are affected by summer SAD, she said.
"[The symptoms are] more dangerous," Safai said. "In recent years we've seen suicide attempts spike in the summer."
Desan said that clinical trials for summer SAD have been limited because in years past there weren't that many people who were forced to stay indoors due to the heat and mental health experts would diagnose the symptoms as other forms of depression.
He predicted that could change given the rise in temperatures.
Summer heat dome raising concerns
The U.S., particularly the West, Southwest and South, have seen record-high temperatures throughout the summer and the psychological experts say that the heat dome will likely result in a jump in summer SAD cases.
Phoenix, Arizona, has recorded over 31 days of temperatures over 110 degrees, which triggered health warnings from city officials to residents to avoid any extended time outdoors during the day.
Desan said that these limits on activities will have short-term mental health effects on people living in their heat domes.
"You never want to lose sight of all of the things you do to maintain well-being for life," he said. "So when you can't see your friends and family, or go for a morning walk or maintain that routine for days or weeks, the [summer SAD] symptoms will emerge."
Desan also said there are extra mental health effects for residents who don't have access to an air conditioner or cool location during the hottest hours, and are forced to deal with the heat indoors with little relief for weeks on end.
He noted that the feelings of despair were similar for residents in the north during this summer's wildfire smoke that covered the Midwest and East for days and limited outdoor time.
He said that climate change-induced phenomenon also prompted mental health issues related to fear, he said.
"That was distressing. Some days it looked like the end of the world because the skies were so dark," he said. "We really haven't seen it before and need to be prepared."
How people can cope
Desan and Safai predicted that more data on summer SAD will be coming through as psychologists and psychiatrists treat more cases brought out by this summer's heat.
"Practitioners need to be ready now and in the fall," Safai said. "[They] really need to be vigilant of the symptoms that people are showing."
Desan said that while there isn't a specific treatment for the disorder, like the winter SAD, anyone who feels like they are suffering from it should reach out to a mental health professional for an appointment.
In the long term, he said the psychiatric community and public health services need to raise awareness for the issue, as weather forecasters predict more extreme heat will be coming to more parts of the country in the years to come.
"Our country really needs to rethink its approach to mental health in general. Climate change will force us to do so," Desan said.
If you or someone you know are experiencing suicidal, substance use or other mental health crises please call or text 988. You will reach a trained crisis counselor for free, 24 hours a day, seven days a week. You can also go to 988lifeline.org.