Heat-related illnesses (HRIs) represent a growing public health concern worldwide, particularly as global temperatures continue to rise due to climate change. HRIs encompass a spectrum of conditions, ranging from mild heat cramps and heat exhaustion to life-threatening heatstroke. They occur when the human body fails to adequately dissipate heat, resulting in physiological stress and organ dysfunction. Vulnerable populations, including the elderly, children, individuals with pre-existing health conditions, and outdoor workers, are disproportionately affected. According to the Centers for Disease Control and Prevention (CDC), approximately 67,500 emergency department (ED) visits annually in the United States are attributable to HRIs, underscoring their significance as a preventable cause of morbidity and mortality [1]. Rural areas face unique challenges regarding the burden of HRIs. Rural residents are more likely to be exposed to occupational heat stress through farming, construction, and other outdoor labor-intensive activities. Limited access to healthcare infrastructure, longer travel times to emergency facilities, and lower socioeconomic resources amplify the risks associated with extreme heat exposure. A study conducted in rural Texas demonstrated significantly higher rates of heat-related ED visits compared to urban counterparts, highlighting disparities in healthcare accessibility and resilience to environmental hazards [2]. Similarly, research in India and other low- and middle-income countries has revealed disproportionate impacts of HRIs in rural populations, often linked to agricultural practices, lack of cooling resources, and insufficient health awareness campaigns [3]. Environmental and climatic factors also play a crucial role in shaping the incidence of HRIs in rural settings. Heatwaves, defined as prolonged periods of excessively high temperatures, are becoming more frequent and severe. The Intergovernmental Panel on Climate Change (IPCC) projects that South Asia and parts of North America will face more frequent extreme heat events, which could exacerbate rural vulnerabilities [4]. Unlike urban areas, where the "urban heat island" effect intensifies localized heat exposure, rural regions may lack adequate monitoring systems, leaving populations underprepared to respond to sudden temperature surges. Emergency department utilization provides an important metric for understanding the burden of HRIs. ED visit data offers insights into temporal trends, seasonal variations, and demographic profiles of affected individuals. Retrospective studies using ED records have been particularly valuable in quantifying the impact of heat on health outcomes, as they provide population-level data that can inform public health interventions and policy. However, much of the existing literature has focused on urban settings, with fewer studies examining rural ED trends specifically. This gap in knowledge limits the development of targeted interventions to protect rural populations. Understanding the patterns and determinants of heat-related ED visits in rural areas is essential for informing prevention strategies, resource allocation, and healthcare preparedness. By analyzing retrospective ED data, researchers can identify high-risk subgroups, peak seasonal burdens, and geographic hotspots. Such evidence can support the design of rural-specific interventions, including early warning systems, occupational safety regulations, community education, and infrastructure improvements, such as cooling centers. This study aims to examine the epidemiology of heat-related illnesses and emergency department visits in rural areas using retrospective data. Specifically, it seeks to characterize demographic patterns, seasonal trends, and clinical outcomes associated with HRIs. By focusing on rural populations, this research will contribute to filling the existing knowledge gap and provide actionable evidence to inform rural health policies in the era of climate change.

This retrospective study will be conducted using data extracted from emergency department (ED) records of rural hospitals over a five-year period (2018–2022). The study will include all patients presenting to the ED with a primary or secondary diagnosis of heat-related illness (HRI), as identified using the International Classification of Diseases, 10th Revision (ICD-10) codes relevant to heat exposure, heat exhaustion, heat cramps, and heatstroke. Cases unrelated to environmental heat exposure (e.g., fever-induced hyperthermia, drug-related heat illness) will be excluded. Study Setting and Population The study will focus on hospitals located in rural regions, defined according to national census classifications. Data will be collected from multiple sites to improve representativeness. The target population will include individuals of all ages and genders who sought emergency care for HRIs during the study period. Data Collection Patient-level information will be extracted from hospital medical records, including: • Demographics: age, gender, occupation, and residence. • Clinical data: type of HRI, comorbidities, presenting symptoms, treatment provided, and outcomes (discharge, hospitalization, or mortality). • Environmental data: date of admission, with cross-referencing to meteorological data (daily maximum temperature, humidity, and heat index) obtained from regional weather services. All data will be anonymized prior to analysis to protect patient confidentiality. Institutional ethical approval will be sought prior to study commencement. Statistical Analysis Descriptive statistics will be used to summarize demographic and clinical characteristics of HRI cases. Categorical variables (e.g., gender, occupation, outcomes) will be presented as frequencies and percentages, while continuous variables (e.g., age, length of stay) will be summarized as means ± standard deviations or medians with interquartile ranges, depending on distribution. Temporal trends will be analyzed by examining monthly and seasonal variations in HRI cases. Inferential statistics will include chi-square tests for categorical comparisons and t-tests or Mann–Whitney U tests for continuous variables. Logistic regression will be used to identify predictors of hospitalization and adverse outcomes, such as advanced age, comorbidities, or occupational exposure. Associations between meteorological variables and ED visits will be assessed using correlation and regression analyses. Limitations Potential limitations include reliance on accurate ICD-10 coding, underreporting of mild HRIs not requiring ED care, and limited generalizability to urban populations. Despite these constraints, this study provides valuable insights into the epidemiology of HRIs in underserved rural regions.

Narrative Findings A total of 2,415 cases of heat-related illnesses (HRIs) were identified across rural emergency departments (EDs) during the study period (2018–2022). The majority of patients were male (62.4%), with a median age of 47 years (interquartile range: 32–64 years). Agricultural and outdoor workers comprised nearly 40% of all cases, reflecting occupational exposure as a significant risk factor (Table 1). Seasonal analysis revealed that summer months (May–August) accounted for more than two-thirds (68.9%) of all ED visits. Peaks in cases coincided with heatwave events, particularly in 2019 and 2021, when daily maximum temperatures exceeded 40°C for consecutive days. Elderly patients (≥65 years) were disproportionately represented during these peaks, with higher rates of hospitalization compared to younger groups (Table 2). Clinical categorization showed that heat exhaustion (54.2%) was the most frequent diagnosis, followed by heat cramps (24.6%) and heatstroke (21.2%). Heatstroke cases carried the highest risk of complications and adverse outcomes, including 9.5% mortality among admitted patients. Comorbid conditions, such as cardiovascular disease and diabetes, were significantly associated with progression to severe HRIs (Table 3). Outcomes analysis demonstrated that 71.3% of patients were discharged after stabilization, while 24.5% required hospital admission and 4.2% died during ED stay or hospitalization. Mortality was concentrated among older adults and those presenting with heatstroke. Logistic regression indicated that age ≥65 years (OR: 2.8; 95% CI: 1.9–4.3), pre-existing cardiovascular disease (OR: 2.3; 95% CI: 1.5–3.7), and outdoor occupational exposure (OR: 1.9; 95% CI: 1.2–3.0) were independent predictors of hospitalization or death (Table 4). Tables Table 1. Demographic and Occupational Characteristics of Patients with Heat-Related Illnesses (n = 2,415) Variable Frequency (n) Percentage (%) Gender Male 1,508 62.4 Female 907 37.6 Age group <18 years 188 7.8 18–44 years 916 37.9 45–64 years 732 30.3 ≥65 years 579 24.0 Occupation Agricultural/outdoor work 956 39.6 Indoor laborers 534 22.1 Students 271 11.2 Homemakers 287 11.9 Unemployed/retired 367 15.2 Table 2. Seasonal Distribution of Heat-Related Emergency Department Visits (2018–2022) Season Cases (n) Percentage (%) Summer (May–Aug) 1,663 68.9 Spring (Mar–Apr) 315 13.0 Autumn (Sep–Oct) 292 12.1 Winter (Nov–Feb) 145 6.0 Table 3. Clinical Classification and Outcomes of Heat-Related Illnesses Diagnosis Frequency (n) Percentage (%) Mortality (%) Heat exhaustion 1,309 54.2 1.1 Heat cramps 594 24.6 0.0 Heatstroke 512 21.2 9.5 Table 4. Predictors of Hospitalization or Mortality in Heat-Related Illnesses Variable Odds Ratio (OR) 95% Confidence Interval (CI) p-value Age ≥65 years 2.8 1.9–4.3 <0.001 Cardiovascular disease 2.3 1.5–3.7 0.002 Diabetes mellitus 1.7 1.1–2.9 0.024 Agricultural/outdoor occupation 1.9 1.2–3.0 0.011

The present study highlights the substantial burden of heat-related illnesses (HRIs) in rural emergency departments (EDs), emphasizing the interplay of demographic, occupational, and climatic risk factors. Our findings revealed that males, agricultural workers, and the elderly were disproportionately represented among HRI cases, consistent with global epidemiological patterns. The predominance of outdoor occupational exposure among affected individuals underscores the vulnerability of rural populations engaged in farming and manual labor [11]. In rural India, for instance, farm workers spend prolonged hours in direct sunlight without adequate hydration or protective measures, thereby increasing their susceptibility to heat stress [12]. Similarly, U.S. data show elevated rates of HRI-related ED visits among construction and agricultural workers, Reflecting occupational hazards intensified by climate change [13]. Seasonal analysis indicated that the majority of ED visits occurred during the summer months, particularly coinciding with heatwave events. This pattern is well established in the literature, with studies demonstrating a clear correlation between extreme ambient temperatures and spikes in ED utilization [14]. Heatwaves are increasingly frequent and intense due to global warming, with rural areas often lacking adequate infrastructure—such as air conditioning, cooling centers, or early warning systems—to buffer their populations from extreme temperatures [15]. Unlike urban “heat islands,” rural regions face challenges of sparse health facilities and limited transportation, resulting in delayed access to care and poorer outcomes [16]. The clinical distribution observed in our cohort, where heat exhaustion was most common but heatstroke carried the highest mortality, aligns with previous reports. Heatstroke, characterized by multi-organ dysfunction and central nervous system involvement, remains the most lethal manifestation of HRI [17]. The observed 9.5% mortality rate in our heatstroke cases is comparable to rural cohorts in South Asia and the southern United States, where mortality has ranged from 7% to 12% [18]. These findings reinforce the urgent need for early recognition and aggressive management of heatstroke at the ED level, particularly in resource-constrained rural hospitals. Our regression analysis demonstrated that advanced age, cardiovascular disease, diabetes, and outdoor occupational exposure were independent predictors of hospitalization and mortality. Elderly individuals have diminished thermoregulatory capacity and are more likely to have comorbid conditions that exacerbate the physiological strain of heat exposure [19]. Cardiovascular and metabolic diseases compound the risk of dehydration, electrolyte imbalance, and poor outcomes. These findings mirror studies conducted in France and Japan, where older adults accounted for the majority of heatwave-related hospitalizations and deaths [20]. From a public health perspective, the results of this study have several implications. First, rural healthcare systems require targeted interventions to mitigate HRI burden. These include community-based awareness campaigns on hydration and heat protection, distribution of low-cost cooling devices, and establishment of seasonal surveillance systems to anticipate peaks in ED visits. Second, occupational safety regulations for farm and construction workers need reinforcement, with mandates on work-rest cycles, shaded rest areas, and employer-provided hydration strategies. Third, integration of meteorological forecasting with health alerts can enable timely community responses and ED preparedness. Importantly, this study contributes to filling a gap in the literature, as much of the existing evidence on HRIs has focused on urban or metropolitan settings. Rural populations, though smaller, are at greater risk due to occupational and infrastructural vulnerabilities. The findings also align with broader climate change projections, suggesting that without adaptation measures, rural health systems will face increasing strain from heat-related emergencies in the coming decades. Nonetheless, some limitations must be acknowledged. This retrospective analysis relied on ICD-10 coding, which may underreport or misclassify mild HRIs not requiring ED care. Additionally, our dataset excluded pre-hospital fatalities, likely underestimating the true burden of severe heatstroke in remote regions. The generalizability of these findings to urban areas is limited, but the focus on rural populations provides valuable context for health policy. Future research should employ prospective surveillance systems and integrate environmental exposure data (e.g., wearable heat sensors, satellite-based climate monitoring) to more accurately capture heat-health interactions. In summary, this study confirms that HRIs remain a pressing rural health challenge, disproportionately affecting vulnerable populations during seasonal peaks. With climate change predicted to intensify heat exposure, strengthening rural health infrastructure and implementing proactive adaptation strategies is essential to reduce preventable morbidity and mortality.

This retrospective study demonstrates that heat-related illnesses contribute significantly to rural emergency department visits, particularly during summer heatwaves. Agricultural workers, the elderly, and individuals with cardiovascular or metabolic comorbidities were most vulnerable, with heatstroke carrying the highest risk of mortality. The findings underscore the urgent need for rural-specific interventions, including occupational protections, public awareness campaigns, and integration of climate forecasts into health preparedness. Strengthening rural healthcare systems and developing early warning mechanisms will be crucial to mitigate the impact of rising global temperatures on vulnerable populations.

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