Impact of Extreme Heat Events on Emergency Department Visits in North Carolina (2007–2011)
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Extreme heat is the leading cause of w eather-related mortality in the U.S. Extreme heat also affects human health through heat stress and can exacerbate underlying medical conditions that lead to increased morbidity and mortality. In this study, data on emergency department (ED) visits for heat-related illness (HRI) and other selected diseases were analyzed during three heat events across North Carolina from 2007 to 2011. These heat events were identified based on the issuance and verification of heat products from local National Weather Service forecast offices (i.e. Heat Advisory, Heat Watch, and Excessive Heat Warning). The observed number of ED visits during these events were compared to the expected number of ED visits during several control periods to determine excess morbidity resulting from extreme heat. All recorded diagnoses were analyzed for each ED visit, thereby providing insight into the specific pathophysiological mechanisms and underlying health conditions associated with exposure to extreme heat. The most common form of HRI was heat exhaustion, while the percentage of visits with heat stroke was relatively low (<10 %). The elderly (>65 years of age) were at greatest risk for HRI during the early summer heat event (8.9 visits per 100,000), while young and middle age adults (18–44 years of age) were at greatest risk during the mid-summer event (6.3 visits per 100,000). Many of these visits were likely due to work-related exposure. The most vulnerable demographic during the late summer heat event was adolescents (15–17 years of age), which may relate to the timing of organized sports. This demographic also exhibited the highest visit rate for HRI among all three heat events (10.5 visits per 100,000). Significant increases (p < 0.05) in visits with cardiovascular and cerebrovascular diseases were noted during the three heat events (3–8 %). The greatest increases were found in visits with hypotension during the late summer event (23 %) and sequelae during the early summer event (30 %), while decreases were noted for visits with hemorrhagic stroke during the middle and late summer events (13–24 %) and for visits with aneurysm during the early summer event (15 %). Significant increases were also noted in visits with respiratory diseases (5–7 %). The greatest increases in this category were found in visits with pneumonia and influenza (16 %), bronchitis and emphysema (12 %), and COPD (14 %) during the early summer event. Significant increases in visits with nervous system disorders were also found during the early summer event (16 %), while increases in visits with diabetes were noted during the mid-summer event (10 %).
KeywordsHeat-related illness Extreme heat Emergency department Morbidity
We thank Nick Petro from the Raleigh, NC National Weather Service office for providing the archived heat products. This project was developed with support from the Regional Climate Center and Regional Integrated Sciences and Assessments Programs, through the National Oceanic and Atmospheric Administration, as well as the North Carolina Division of Public Health.
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Conflict of interest
- 1.National Oceanic and Atmospheric Administration. (2015). Natural hazard statistics. National Weather Service, Office of Climate, Water, and Weather Services. http://www.nws.noaa.gov/om/hazstats.html.
- 2.Centers for Disease Control and Prevention. (2006). Heat-related deaths—United States, 1999–2003. Morbidity and Mortality Weekly Report, 55(29), 796–798.Google Scholar
- 3.Harvard Medical School. (2005). Climate change futures: Health, ecological and economic dimensions. Cambridge, MA: Center for Health and the Global Environment, Harvard Medical School.Google Scholar
- 13.Kalkstein, L. S., Sheridan, S. C., & Kalkstein, A. J. (2009). Heat/health warning systems: Development, implementation, and intervention activities. In K. L. Ebi, I. Burton, & G. McGregor (Eds.), Biometeorology for adaptation to climate variability and change (pp. 33–48). Heidelberg: Springer.CrossRefGoogle Scholar
- 14.Hajat, S., Sheridan, S. C., Allen, M. J., Pascal, M., Laaidi, K., Yagouti, A., et al. (2010). Heat-health warning systems: A comparison of the predictive capacity of different approaches to identifying dangerously hot days. American Journal of Public Health, 100(6), 1137–1144.PubMedPubMedCentralCrossRefGoogle Scholar
- 26.North Carolina Department of Public Health. (2012). Strategic plan for addressing health impacts of climate change in North Carolina. http://epi.publichealth.nc.gov/oee/climate/ClimateReadyStrategicPlan.pdf.
- 27.National Oceanic and Atmospheric Administration. (2015). National Weather Service Raleigh, products and services guide. http://www.erh.noaa.gov/rah/criteria.
- 32.Wheeler, K., Lane, K., Walters, S., & Matte, T. (2013). Heat-related deaths—New York City, 2000–2011. Morbidity and Mortality Weekly Report, 62(31), 617–621.Google Scholar
- 33.Gubernot, D. M., Anderson, G. B., & Hunting, K. L. (2014). The epidemiology of occupational heat exposure in the United States: A review of the literature and assessment of research needs in a changing climate. International Journal of Biometeorology, 58, 1779–1788.PubMedPubMedCentralCrossRefGoogle Scholar
- 45.Harlan, S. L., Chowell, G., Yang, S., Petitti, D. B., Morales Butler, E. J., Ruddell, B. L., & Ruddell, D. M. (2014). Heat-related deaths in hot cities: Estimates of human tolerance to high temperature thresholds. International Journal of Environmental Research and Public Health, 11(3), 3304–3326.PubMedPubMedCentralCrossRefGoogle Scholar
- 47.Muresanu, D. F., & Sharma, H. S. (2007). Chronic hypertension aggravates heat stress induced cognitive dysfunction and brain pathology: An experimental study in the rat, using growth hormone therapy and possible neuroprotection. Annals of the New York Academy of Sciences, 1122, 1–22.PubMedCrossRefGoogle Scholar