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Member Research & Reports

Member Research & Reports

Washington Finds Extreme Heat Increases Emergency Medical Service Calls for Workers

While temperatures in the Pacific Northwest are generally perceived as moderate, when heat events do occur, the area may be vulnerable. New findings from the University of Washington School of Public Health show increased risk for heat illness and dehydration on hotter days for the working-aged population between the ages of 15-64.

Miriam Calkins 2016
[Photo: Ms. Miriam Calkins]

“The demand for Emergency Medical Services during heat events shows a burden on the population and healthcare system in King County that isn’t necessarily reflected in hospitalization or mortality data,” said lead researcher Ms. Miriam Calkins, a PhD student in the department of environmental and occupational health sciences at Washington. She added that the study’s results could help planners understand health effects from climate change by considering EMS data in their assessment.

Ms. Calkins used Emergency Medical Services (EMS) call data from Public Health Seattle – King County between May 1 and September 30 for each year from 2007 to 2012. She analyzed meteorological data for the same time period using humidex, a temperature index that combines the effect of heat and humidity to gauge how hot the weather feels to a person. EMS responds to all calls with basic life support and supplies advanced life support to more critical cases.

Ms. Calkins  found that a humidex at or above 29.7 degrees Celsius (85.5 degrees Fahrenheit) increased risk for basic life support call response by 8 percent. A humidex at or above 36.7 degrees Celsius (98 degrees Fahrenheit) increased risk of advanced life support call response by 14 percent for all ages and all causes as compared to non-heat days below these humidex temperatures.

The study found that the greatest, most frequent calls – regardless of health condition – came from the working population between 15 and 64 years old, a surprising finding for an age group generally considered resilient.

In addition, the study found that EMS calls on hotter days increased for abdominal and genitourinary conditions, anaphylaxis and allergy reactions, and conditions also linked to alcohol and drug use. These new findings, Ms. Calkins said, indicate that research on health effects from heat may need to include these for a more comprehensive list of adverse outcomes.

Other researchers involved in the study include Dr. Tania Busch Isaksen, Mr. Benjamin Stubbs, Dr. Michael Yost, and Dr. Richard Fenske.