July's deadly surge: Is heat fueling overdose deaths?

The Hidden Connection Between Heat and Drug Overdoses in Los Angeles

While Los Angeles has seen a significant decline in drug overdose deaths in recent years, one month stands out as the most deadly in the past decade. According to the county health department, July recorded 1,894 drug-related deaths over the last ten years. This alarming figure raises questions about the role of extreme heat in exacerbating the risks associated with drug use.

Experts suggest that high temperatures may be a key factor in many of these deaths. Bharat Venkat, a UCLA professor and director of the university’s Heat Lab, believes that a substantial number of these fatalities could be linked to extreme heat exposure. “Opioids can alter your internal temperature regulation,” he explained. “They might slow down the body’s ability to sweat, making it harder to cool down.”

Dr. Pope Moseley, a lung and critical care physician who has studied the effects of heat on drug toxicity, added that opioids can impair heat exchange through the skin and increase gut permeability. This can lead to serious conditions like heatstroke, respiratory failure, or sepsis. Additionally, the sedative effects of opioids can leave users too drowsy to seek shelter or help when they become overheated.

Methamphetamine presents a different set of challenges. It can make individuals more agitated and physically active, which increases their risk of overheating in hot conditions. In both cases, drug use can hinder a person's ability to respond to environmental heat—whether by cooling off or recognizing danger.

Public cooling centers are designed to protect vulnerable populations from extreme heat, but experts say they often exclude those using drugs. Dr. José Luis González, medical director of Healthcare in Action, noted that many cooling centers may not allow individuals who appear to be under the influence of opioids or meth. This exclusion leaves the most at-risk group without access to critical resources.

Despite growing evidence of heat's role in drug-related deaths, officials in Los Angeles remain skeptical. A spokesperson for the Los Angeles County Department of Public Health stated that the issue is more about people being indoors during bad weather and using drugs alone, rather than the heat itself. However, data from the health department shows only 118 heat-related deaths between 2015 and 2024. Experts argue this number is likely an underestimate, as previous analysis has shown that heat often exacerbates chronic conditions but isn't always recorded as a contributing factor.

The way death certificates are written plays a crucial role in accurately capturing the impact of heat on mortality. Dr. Christina VandePol, former coroner of Chester County, Pa., pointed out that there are no standardized guidelines for certifying heat-related deaths. While resources exist, such as CDC guidelines on disaster-related deaths, they are largely advisory. In contrast, some states like Arizona have implemented protocols requiring investigators to consider heat in deaths occurring between April and October. These efforts led to a dramatic increase in reported heat-related deaths in Maricopa County from 61 in 2014 to 645 in 2023.

In Los Angeles County, the process of attributing heat as a cause or contributing factor to a death is highly discretionary. Dr. Odey C. Ukpo, the county’s chief medical examiner and coroner, said that each investigator considers the circumstances surrounding a death individually. Heat-related deaths are often classified as a diagnosis of exclusion, meaning they are only cited after all other causes have been ruled out.

Determining whether a death is "drug-related" involves examining the body, ruling out injury or natural disease, and conducting toxicology reports. Contrary to common belief, there is no set threshold for how much of a substance is considered lethal. “It’s more about deductive reasoning,” Ukpo said. “Any level of a toxin can kill someone.”

This lack of uniform standards across jurisdictions raises concerns among public health experts about potential underreporting. VandePol emphasized that without accurate data, it's impossible to address underlying issues. “If you don’t know a problem exists, you can’t fix it.”

Some counties, like Santa Clara, have made strides in documenting environmental factors in death records. While imperfect, their approach offers a better model than what Los Angeles currently provides.

Ukpo expressed openness to improving the process, noting recent efforts to integrate epidemiological analysis into death investigations. “We’ve hired our first epidemiologist,” he said. “We’re looking at cases, planning heat maps, and tracking trends to better understand these issues.”

However, the politicization of climate-related issues under the current administration has complicated the discussion. VandePol called the intersection of heat and drug overdoses a “political football.” The disparities in how these deaths are certified and reported highlight broader systemic issues that may obscure the true impact of climate-related health risks in Los Angeles.

“We need to start recognizing that heat is a killer,” Moseley said. Addressing this issue requires a more consistent and transparent approach to death certification and public health response.