Indiana State University Newsroom

Athletic training students study impact of heat on firefighters

August 25, 2010

Firefighters already accustomed to the oppressive heat of real fires filed down the stairs of a five-story training structure in northern Terre Haute. The smoke - albeit fake - was so thick it shrouded the room in almost total darkness.

Dave Dziedzicki, a graduate assistant in Indiana State University's athletic training department, waited at the bottom. Wearing a T-shirt and shorts, he measured the men's reaction to high body temperatures.

Once outside in 80-degree sunny weather, he marveled at how the firefighters could withstand so much heat - even if it was all just practice.

"They've seen a lot worse than a training session," Dziedzicki said.

Indiana State's department of applied medicine and rehabilitation partnered with the Terre Haute Fire Department in August to study the effect extreme heat has on a firefighter's body. Participants swallowed a thermometer pill and performed various exercises staged to depict emergency situations. In each situation, the firefighters used different cooling mechanisms so that their effectiveness could be compared.

The researchers measured the firefighters' hydration levels before and after training and how well or not well they stayed hydrated. During training, the firefighters' average sweat and heart rates, core body temperatures and cognitive brain functions were tracked.

"This is probably the best study I've ever had," said study leader Susan Yeargin, assistant professor of athletic training. She credited all of the help available, from both the graduate assistants and fire department.

The three-day study was divided into 15-minute work periods with time for an oxygen bottle exchange and rehabilitation session. Besides the high-rise structure, firefighters also participated in a search-and-rescue obstacle course meant to simulate a wall breach and involving the retrieval of "Rescue Randy," a life-size training doll. Another search-and-rescue exercise required firefighters to work in complete darkness. There was also a vehicle extrication simulation.

Amy McKenzie, an athletic training graduate student who comes from a family of firefighters, used a stopwatch and a bullhorn to keep the firefighters on schedule.

"[It has all] went really smoothly," McKenzie said before yelling a two-minute warning into the bullhorn. She plans to use data collected from the study in her master's thesis about head cooling mechanisms.

Located near Terre Haute North Vigo High School, the training facility is the first of its kind built in Indiana, said Norm Loudermilk, the fire department's training chief. The facility is a designated Department of Homeland Security Region 7 facility, serving Vigo and surrounding counties.

"This has been a very good exercise just to show us where we are," said Loudermilk, who also serves as the department's arson investigator.

Recent heat waves have not caused problems for the crew during actual calls this summer, thanks to an abundance of manpower able to provide quick relief.

"Heat is always an issue for us," Loudermilk said. "We have to manage our people well."

Temperatures inside a burning room can reach 2,200 degrees, he said. If a room is 250 degrees, the human body can only sustain itself for less than an hour and a half.

For some people, body functions shut down at 104 degrees due to damage from heat stroke, McKenzie said.

"It could change based on how heat-acclimated you are," she said.

Derek Kingsley, assistant professor of physical education who is assisting with the study, said some firefighters registered 105 degree temperatures after training.

During the rehabilitation sessions, firefighters stripped off most of their gear and had their hydration and cognitive levels tested. Some settled into rehab chairs specially fitted with troughs of icy water designed to cool the body temperature.

Such devices are constantly marketed to firefighters, but without any reliable proof of effectiveness, Yeargin said. While pursuing her master's degree at the University of Florida and working with firefighters in Gainesville, she said the firefighters would ask her about cooling methods.

Equally concerned were firefighters in Connecticut, where she earned her Ph.D.

"I want to be able to give them a real answer," she said.

Yeargin hopes to have all the data they collected analyzed by November and ready for publication in prominent firefighter trade journals next summer. She also plans on having the work published in an occupational physiology journal.

Video: Watch the WTHI-TV report at

Photos: - Megan Finn, a graduate student in athletic training at Indiana State University, examines Terre Haute firefighter Joe Swan during a training exercise in which students researched the impact of heat on the human body. (ISU/Gurinder Singh) - Terre Haute firefighters train in a room filled with simulated smoke during an exercise in which athletic training graduate students at Indiana State University studied the impact of heat on the human body. (ISU/Gurinder Singh)

Contact: Susan Yeargin, assistant professor of athletic training; 812-237-3962 or

Writer: Nick Hedrick, media relations assistant, Indiana State University, Communications and Marketing, 812-237-3773 or