In the center of the living room of Maria Montano's apartment wall is a large photograph of her older brother, Brandon: photos of the family trip to the beach, some funny selfies and, in the middle, a big close-up of his brother's face, brown eyes staring upward.

“I remember him always smiling and happy,” Maria said.

Maria said she loved taking care of Brandon when they were kids. Though he was only five years younger than her, she thought of him as her little son. After they grew up, Brandon struggled with addiction. Still, Maria always tried to look after him.

“I tried to get him into rehab, I tried to get him into therapy, I had a lot of conversations with probation officers about how to help him,” Maria said.

Without stable housing, Malia would sometimes let Brandon stay at her house. Brandon left Malia's house for the last time on July 20 of last year, one of the hottest days in Phoenix history, with temperatures reaching 119 degrees.

Later that day, a passerby found Brandon unresponsive in the street. Paramedics rushed him to the hospital, where his temperature was recorded as 106 degrees. He did not survive.

It was days before Maria found out about Brandon's death, and months before she received the coroner's report on his case, which listed methamphetamine and fentanyl intoxication as Brandon's cause of death, but to her surprise, it also listed another cause of death: environmental heat exposure.

“I always [heat-related deaths were] “People who hike or exercise aren't used to it,” Maria says.

She and Brandon grew up in Arizona and were used to the heat, but Malia didn't realize that extreme temperatures would make her brother's drug use more dangerous — and she doesn't think Brandon knew that either.

“I don't think he really thought about it,” Maria said.

The circumstances that led to Brandon's death are becoming increasingly common. Maricopa County has seen a sharp increase in heatstroke deaths in recent years. Last year, a record-breaking 645 people died from heatstroke. Rising summer temperatures due to climate change are contributing to the trend, as is an increase in homelessness, leaving more people vulnerable to heatstroke. But another big factor in the rising death toll is substance use. As heatstroke deaths have skyrocketed in Maricopa County, so has the percentage of deaths involving drugs and alcohol. Last year, two-thirds of heatstroke cases were drug-related.

The most frequent culprit was methamphetamine, one of the drugs Brandon used.

Maricopa County Public Health

“I've personally seen an increase in stimulant use in the communities we serve,” said Jonathan Garcia, clinical director for Community Bridges, a behavioral health organization that runs several shelters and crisis response programs in the Phoenix metropolitan area and contracts with the city of Phoenix for substance use intervention programs.

“Methamphetamine is [substance] “I understand,” Garcia said.

Garcia said methamphetamine has become popular because it's relatively cheap and easy to obtain, and for the homeless people he helps, the powerful stimulant provides an appealing burst of energy.

“They're saying you have to stay awake to protect yourself, you have to watch your belongings,” Garcia said.

Katherine Davis Young/KJZZ

Methamphetamine can keep people awake for days, Garcia said. That's dangerous in itself, but the drug also increases heart rate, raises body temperature, reduces thirst and even reduces the feeling of heat. Combined with Arizona's scorching summer weather, even a small amount of methamphetamine can be deadly.

Last year, 330 people died in Maricopa County from methamphetamine use and heat stroke, nearly triple the number of methamphetamine and heat stroke deaths just three years earlier. According to Maricopa County records.

“Opiates, fentanyl, heroin get a lot of attention, and rightfully so, overdoses are happening with those, but methamphetamine is kind of swept under the rug and doesn't get as much attention,” Garcia said. “I think we need more education and resources around methamphetamine.”

Arizonans have one of the highest methamphetamine-related death rates in the nation. Centers for Disease Control and Prevention State Unintentional Drug Overdose Reporting System.

Nicole Witt, public health adviser for the city of Phoenix, believes climate is partly to blame.

“In Arizona, I think we're at the forefront of talking about this issue,” Witt said.

Witt said: CDC Data Drug overdose deaths across the U.S. typically occur roughly evenly from month to month. That's not the case in Arizona.

“It's a very unique curve for Arizona, where we're seeing this surge in the summer months, particularly in July,” Witt said.

Phoenix officials this year wanted to make substance abuse a bigger focus in the city's plan to prevent heatstroke deaths, but Witt said when she and her colleagues went looking for resources to guide the city's approach to this growing public health problem, they found almost nothing.

“What we do in public health is look at evidence-based practices and peer-reviewed research on the topic, determine what needs to be done and then tailor it to the local context,” Witt said. “In this case, there aren't really many examples of strategies for this particular topic, which is the combination of heat and drug use.”

So Witt and his colleagues decided to write a new pamphlet from scratch, to be distributed this summer through drug intervention organizations in the Phoenix metropolitan area. The pamphlet encourages stimulant users to drink plenty of fluids and recognize the symptoms of heatstroke. It also offers advice to limit drug use to air-conditioned areas and not to use drugs alone.

But it will take time to raise awareness about the dangers of the drug and heat and for authorities to understand the most effective interventions to prevent these deaths, Witt said.

“We're really creating something out of nothing,” Witt said.

So far this year, Maricopa County Confirmed Twenty-three people have died from heatstroke, and officials are investigating more than 300 other possible heatstroke deaths. Those figures are 54% higher than the same period last summer. More than half of the confirmed heatstroke deaths this year have involved substance use, according to county records.

As temperatures continue to reach triple digits, Maria said she feels depressed thinking about all the Arizonans who, like her brother, are struggling with drug use.

“I feel like there are a lot of people out there right now who are in the same situation as him and aren't getting enough support,” Maria said.

Brandon was only 25 when he died, and Maria knows he hoped for a better future.

“He told me he wanted to change but couldn't,” Maria said.

She wishes he had been given that chance.