Influence of extreme weather conditions on the deployment volume of emergency medical services

Background Due to global warming a worldwide increase in the frequency and intensity of heat waves have been forecast. In the context of the overall increasing number of emergency service calls, weather-induced effects on the number of calls are highly relevant. We evaluated the influence of extreme temperatures on emergency medical services. Materials and methods The study was conducted in Bochum, Germany. The authors examined the data from 16,767 emergency calls. In addition, the daily updated temperature data were collected for each emergency doctor call. Data were collected from 01 January 2014 until 31 December 2015. The primary question was the influence of extremes of the perceived temperature (PT; on the day of the call and the three previous days) on the diagnosis group of cardiovascular diseases. A secondary question was the influence of extremes of the temperature parameters (air temperature, PT, physiological equivalent temperature [PET]) on the day of call and the three previous days. Results A total of 16,767 calls were assessed. The threshold values (upper and lower 5%) were -8.7 and 32.5 degrees C for PT and -0.7 and 26.7 degrees C for air temperature. Examination of the PT indicated a significantly increased rate of calls for cold spells on the day of the call (RR= 1.14; p= 0.033) as well as a lag effect of 3 days (RR= 1.1; p= 0.049). Conclusion The present study shows that during cold spells there is an increased rate of calls for cardiovascular diseases. This effect is not only observable on the extreme day itself but also 3 days later.