title: Relationship between ambient temperature and frequency and severity of cardiovascular emergencies: A prospective observational study based on out-of-hospital care data.
abstract: OBJECTIVE
  To test the hypothesis that more cardiovascular emergencies occur at low rather than at high temperatures under moderate climatic conditions.
  
  
  METHODS
  This was a prospective observational study performed in a prehospital setting. Data from the Emergency Medical Service in Hamburg (Germany) and from the local weather station were evaluated over a 5-year period. Temperature data were matched with the associated rescue mission data. Lowess-Regression analysis was performed to assess the relationship between the temperature and the frequency of individual cardiovascular emergencies. In addition, three threshold-temperatures (0°C, 10°C, 20°C) were defined in order to determine the frequency of cardiovascular emergencies above and below each cut-off value. The severity of emergencies was assessed using the National Advisory Committee for Aeronautics (NACA) scoring system.
  
  
  RESULTS
  A total of 35,390 cardiovascular emergencies were treated by Emergency Physicians. Transient Loss of Consciousness increased at high temperatures (above 20°C): +43% (95%-CI: [27%; 59%]). In contrast, Coronary Artery Disease +26% (95%-CI: [17%; 34%]), Cardiac Pulmonary Edema +21% (95%-CI: [14%; 27%]), Hypertensive Urgency +18% (95%-CI: [10%; 25%]) and Cerebrovascular Accident +17% (95%-CI: [8%; 24%]) increased at low temperatures, particularly below 10°C (significance level for all: p<0.001). No temperature-related effect was seen in Cardiac Arrhythmia and Pulmonary Embolism and no significant correlation was found between the severity of emergencies and temperature.
  
  
  CONCLUSIONS
  Our findings suggest that some cardiovascular emergencies such as Coronary Artery Disease, Cardiac Pulmonary Edema, Hypertensive Urgency and Cerebrovascular Accident are more frequent in low temperatures even under mild climatic conditions.
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, Park-Klinik-Weissensee, Schönstrasse 80, 13086 Berlin, Germany. Electronic address: hensel@park-klinik.com.
authors.forename: Mario
authors.initials: M
authors.lastname: Hensel
authors.affiliation: Department of Anesthesiology, Intensive Care and Emergency Medicine, Pain Medicine, BG Klinikum, Bergedorfer Strasse 10, 21033 Hamburg, Germany. Electronic address: m.stuhr@buk-hamburg.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Stuhr
authors.affiliation: Department of Anesthesiology, Intensive Care Medicine, Emergency Medicine, and Pain Therapy, Asklepios Klinik Nord Heidberg, Tangstedter Landstrasse 400, 22417 Hamburg, Germany. Electronic address: dg-hh@freenet.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Geppert
authors.affiliation: Competence Center for Healthcare Research, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany. Electronic address: j.kersten@uke.de.
authors.forename: Jan F
authors.initials: JF
authors.lastname: Kersten
authors.affiliation: Faculty of Life Sciences, Department of Medical Engineering, Hamburg University of Applied Sciences, Lohbrügger Kirchstrasse 65, 21033 Hamburg, Germany. Electronic address: juergen.lorenz@haw-hamburg.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Lorenz
authors.affiliation: Department of Anesthesiology, Intensive Care Medicine, Emergency Medicine and Pain Therapy, Asklepios Klinikum Harburg, Eißendorfer Pferdeweg 52, 21075 Hamburg, Germany. Electronic address: t.kerner@asklepios.com.
authors.forename: Thoralf
authors.initials: T
authors.lastname: Kerner
mesh_terms: D039602:After-Hours Care / Q000706:statistics & numerical data*; D000368:Aged; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D004630:Emergencies / Q000453:epidemiology*; D004781:Environmental Exposure; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013696:Temperature; D013997:Time Factors
keywords: Ambient temperature; Cardiovascular emergency; Emergency physician; Prehospital