MISSOULA — We've already seen quite a few wildfires pop up this season in Western Montana.
For more insight into what working on the front lines requires from firefighters' bodies, MTN connected with Brent Ruby, a physiologist who has spent 25 years researching health, performance, and safety — for mainly hot-shot crews — through Montana’s Center for Work Physiology and Exercise Metabolism.
"Montana is just really well known for fire and it's a part of our landscape. It's a part of our fabric," Ruby expressed.
When wildfire season is in full swing around the West, that means all types of fire crews are too.
“My very first study with fire crews, the focus was to look at what the total energy demands of the job might be,” shared Ruby.
To do so, Ruby used a special method that gave real-time data.
“We used the technique with different stable isotope tracers. We can track them through the body and so we just collect urine samples periodically," he detailed. "The breakdown is, we can calculate total CO2 production and then we can calculate total energy expenditure."
Hiking through rugged landscapes, chopping timber, sawing, and creating fire lines, all play a part in the intense and demanding work firefighters do. That’s what Ruby’s first study confirmed.
“We identified the energy demands to be between 4000 and 6000 calories a day,” he said.
On top of the work requirements, wildland firefighters have to deal with excessive heat.
“We think about the fire, the radiant heat from the fire pushing back at them. We think about the radiant heat from the sun and the environment that they're in. But the forgotten heat is produced in their own bodies by their own muscles,” explained Ruby.
To figure out the impact of heat on the body, Ruby and his team used pill-sized trackers. “Wireless thermometers that we can have them swallow. We can get minute-by-minute body temperature measures,” he noted.
Through the heat, the crews need to fuel themselves and stay properly hydrated. Food and water intake do depend on the size of the person and level of exertion.
“The dietary intake that we've analyzed painstakingly on crews. They seem to be getting enough food and they seem to be getting enough carbohydrate, they certainly get enough protein," Ruby explained.
“We've probably got data on well over 60 to 100 people and anywhere from about 7.5 to about 10 liters every 24 hours is sort of the expected water budget," he continued.
As the season rolls along, Ruby said firefighters feel the impacts, no-matter their fitness level.
“The season takes its toll and we can learn a lot about an individual in that stressful operational environment,” Ruby told MTN.
