Overview
- In persistently hot regions such as Phoenix, study participants were on average about 14 months older biologically than their chronological age.
- The authors cite heat‑triggered inflammation and DNA methylation as plausible pathways but emphasize the findings are observational and causality remains under investigation.
- Health guidance notes the heat index begins to pose hazards around 32°C, with substantially higher risk above about 38°C, particularly with prolonged exposure or high humidity.
- Older adults, outdoor workers and people without dependable cooling face elevated risk, and clinicians urge rapid intervention during heat waves given the short timescale for measurable effects.
- Recommended protections include steady hydration, limiting activity during peak hours, access to cooled spaces, urban shading and outreach to isolated seniors; a neurologist told LA NACION that heat stroke can be fatal and estimated hundreds of thousands of heat‑related deaths worldwide each year.