Tree shade offers critical heat relief for people experiencing unsheltered homelessness

People experiencing unsheltered homelessness in Salt Lake City endure dangerous daytime heat and hot nights, according to a University of Utah study. The research, published in the Journal of Urban Health, highlights that tree shade provides crucial heat relief for this vulnerable population. The study, titled "Trees reduce daytime urban heat risk for people experiencing unsheltered homelessness," was part of a larger report released on October 5 that examined extreme heat and unsheltered homelessness in Salt Lake County, Utah.

Researchers measured heat exposure in real-time over eight days, following eight participants equipped with GPS-enabled cellphones and portable heat sensors. During the day, participants experienced moderate, high, and very high heat conditions, with nighttime offering little respite. Participants spent an average of 69% of nighttime hours above the threshold for hot nights, which can disrupt sleep.

The study found that time under tree canopy reduced heat-index levels by 1.7 to 3.2°F between noon and 6 p.m. Public trees can serve as an alternative to indoor cooling spaces, but access issues often limit the benefits. The authors stress that trees provide public health infrastructure for those without shelter, but they cannot replace secure housing or indoor cooling during extreme heat.

The report urges the implementation of a statewide "Code Red" policy, which would provide emergency protections during dangerous heat, such as extended access to public cooling spaces like libraries and senior centers. The researchers emphasize the importance of prioritizing tree planting and other cooling resources in hotter, underserved neighborhoods, involving people experiencing homelessness in the decision-making process.

They also call for policies that do not displace people from shaded areas, as these investments in urban green spaces can have significant benefits for everyone.