Impact of high temperatures on healthcare utilisation among older adults: a scoping review

Abstract Background Rapid global ageing coincides with rising temperatures and increasing strain on healthcare services. High temperatures are associated with increased healthcare demand, yet evidence on older people’s healthcare utilisation remains fragmented and is often service- or cause-specific. This review synthesises current evidence on high temperatures and healthcare utilisation among older adults, highlighting implications for health system resilience. Methods We investigated the association between high temperatures and healthcare utilisation among older adults. Following PRISMA-ScR guidelines, we searched MEDLINE, EMBASE, PsycINFO, Global Health, CINAHL, and grey literature from 2000 to June 2023. Eligible studies examined healthcare utilisation or delivery during and immediately after high-temperature periods among individuals aged ≥60 years. Data were charted and summarised descriptively. No risk-of-bias assessment was undertaken, consistent with scoping review methodology. Protocol registered on OSF ( https://doi.org/10.17605/OSF.IO/H2Q7V ). Results Of 106 included studies, most employed time-series or case-crossover designs. Acute high-temperature exposure was consistently associated with short-term increases in healthcare utilisation, including ambulance dispatches, Emergency Department (ED) attendance, and emergency hospitalisation. Only 26.2% of studies stratified outcomes by age group, but available evidence suggested stronger effects with advancing age. Associations were consistent across regions and climates. Cause-specific analysis showed an association with increased risk of ED attendance and hospitalisation for heat-related illness and renal, metabolic, and mental health conditions, while associations with cardiovascular and respiratory causes were inconsistent. Most excess admissions occurred within three days of exposure, except for mental health, which lagged by one week. Increased heat risks for outpatient and primary care visits persisted beyond the acute exposure period. Discussion High temperatures are associated with acute increases in healthcare utilisation among older adults worldwide. However, evidence remains geographically skewed, with no studies from Africa or South Asia, regions facing rapid population ageing and high climate vulnerability. Reliance on routinely collected outcomes limited system-level understanding of impacts on care pathways and severity indicators such as hospital length of stay. Future research should prioritise underrepresented settings, incorporate broader outcomes, and apply age-stratified analysis to capture differential vulnerability among older people. This evidence is required to guide climate adaptation strategies and strengthen health systems to protect ageing populations during high-temperature periods.