A new study from Boston University highlights the severe impact of extreme heat on the mortality rates of homeless individuals in Los Angeles and Clark County. As climate change exacerbates heatwaves, researchers call for urgent public health measures and housing reforms.
A recent study conducted by the Boston University School of Public Health (BUSPH) has uncovered a profound link between extreme heat and increased mortality rates among homeless populations. Published in the American Journal of Epidemiology, the research reveals that individuals experiencing homelessness (PEH) face significantly higher mortality risks during hot weather.
The study focused on Clark County, Nevada —including Las Vegas — and Los Angeles County, California, both regions characterized by hot climates and high rates of homelessness.
The researchers found that nearly 50% of deaths in Clark County during the study period were attributable to higher daily temperatures. In Los Angeles County, 5.2% of deaths were heat-related.
“It wasn’t a surprise that our team found an association between heat and mortality for unhoused people, but the magnitude was staggering,” senior and corresponding author Jonathan Jay, an assistant professor of community health sciences at BUSPH, said in a news release. “Our estimates are 10 to 100 times greater than the known associations between daily heat and mortality for the general population in LA and Las Vegas, and this finding highlights the moral imperative for our systems to do more.”
The study’s significance is amplified by the recent unprecedented October heatwave affecting the West Coast, prompting numerous heat alerts and soaring temperatures. Los Angeles and Las Vegas reported peaks of 111 degrees and 104 degrees, respectively. The ongoing high rates of homelessness in these cities underline the urgency of addressing the health impacts of extreme heat on this vulnerable population.
For the study, the researchers collected mortality and daily temperature data from January 2015 to August 2022 for Clark County and until November 2022 for Los Angeles County. By analyzing deaths from all causes, the team ensured that the data reflected the broader impacts of heat, not just direct heat-related incidents like heat stroke or hyperthermia.
Jay emphasized that the findings show the critical need to prioritize marginalized populations in climate and health research.
“It was important to see that deaths increased as daily temperatures increased, from cool days to warmer days, and they spiked on hotter days, starting around 90 degrees Fahrenheit and higher,” he added.
He also noted that the findings suggest public health advocates should extend heat-related support beyond the summer season as climate change exacerbates the frequency and severity of heatwaves.
To mitigate the impact of extreme heat, the study proposes several public health strategies, including the establishment of cooling centers, water stations and urban greening projects.
However, the researchers stress that these measures should be part of a broader “Housing First” approach, given that the primary cause of homelessness is a lack of affordable housing.
“Too much of our policy is driven by the impulse to hide homelessness from view, rather than to recognize people’s dignity, protect their health and improve our systems,” added Jay.
He criticized the recent Supreme Court ruling that permits cities to ban people from sleeping and camping in public places, emphasizing the need for supportive housing policies rather than punitive measures.
The study, led by Zihan Lin, a former postdoctoral fellow at BUSPH and now an assistant professor at Cleveland State University, sheds light on the urgent need for targeted interventions to safeguard the health of homeless individuals amid rising global temperatures.