“It’s 5 a.m. and still dark at the Carlton Complex fire camp in central Washington, except for the fire’s orange glow on a distant ridgeline. Wildlands firefighter Bre Orcasitas, two colleagues, and three volunteers suit up: heavy duty fire-resistant pants, shirt, jacket, and helmet. Their boots weigh 2 kilograms; the backpacks they will haul to the fire—loaded with 6 liters of water, food for a 16-hour shift, safety gear, and hand tools—can weigh 30 kilograms. Sometimes the burden includes a 12-kilogram chain saw.
On this day in August 2014, the crew is not just fighting flames, but also taking part in research. Orcasitas outfits each person with a chest harness and sensors that will record their heart rate, elevation gain, distance traveled, carbon monoxide intake, and skin temperature. Each swallows an ingestible radio thermometer that relays deep body temperature to the chest monitor every 15 seconds via Bluetooth. Orcasitas and her two colleagues will record each firefighter’s activities, be it cutting down trees, digging a fire break, or burning vegetation to keep a larger fire away. It’s all part of a study to assess heat exposure in wildlands firefighters—the biggest ever to do so. From 2013 through 2016, more than 300 firefighters participated.
High body temperatures are inevitable in firefighting: A study in 2013 uncovered about 50 heat-related injuries across the United States during that fire season. But other data from their project have surprised Orcasitas and her colleagues. Warmth from the firefighters’ physical exertion, not heat from the fires, was the greatest danger, the researchers found. Another surprise: “The assumption across the fire community was that if somebody went down, it was because they just didn’t drink enough water,” Orcasitas says. But the team found otherwise. “You can’t drink yourself out of a heat-related injury,” explains project leader Joseph Domitrovich, an exercise physiologist at the U.S. Forest Service’s National Technology and Development Program. “It’s not the magic bullet that people thought.” … article continued at: https://www.sciencemag.org/news/2020/11/heat-killing-more-people-ever-scientists-are-looking-ways-lower-risk