By CRAIG A. HAIGH, ANDREA F. WILKINSON, DENISE L. SMITH,
and LELAND B. HAIGH
“Pick it up and get ready for the next one.” This is an order you have received and given countless times throughout your fire service career. It is how the fire service operates. Companies respond to the emergency, perform the needed tasks, solve the problem, and then repack and reset because you need to be ready to immediately respond to the next call for assistance. This work model is instilled into our newest recruits and reinforced throughout day-to-day practices. Company officers need to make their companies available as soon as possible, and chief officers begin releasing companies from incident scenes quickly, keeping only those essential for final overhaul and scene cleanup. The ability to respond quickly is a mainstay of our service delivery model. Getting companies back into service following an incident is a fundamental function of how the fire service serves its customers.
For firefighters, downtime comes when the hose is repacked, the booster tank is refilled, ladders are placed in their cradles, tools and equipment are stowed, self-contained breathing apparatus bottles are changed/recharged, and they have notified dispatch that they are available for the next run.
The prevailing thinking has been that once the intense workload of managing the incident ceased, the period of cleanup and reset served as a sort of a rest for firefighters. The pace slows, and the firefighters often work while wearing less personal protective equipment (PPE). However, this notion has been recently challenged by research data obtained during our participation in the SMARTER project.
The SMARTER Project
SMARTER is an acronym for Science Medicine And Research Technology Emergency Responders, a project led by the Skidmore College First Responder Health and Safety Laboratory and funded by the Federal Emergency Management Agency Assistance to Firefighter Grant Program (EMW-1015-FP-00731). The Hanover Park (IL) Fire Department (HPFD), in partnership with Skidmore College, provided 54 firefighters of various ranks to participate in the evaluation and field testing of commercially available physiological status monitors (PSM). The project includes evaluating wearable technology that monitors physiological variables of firefighters while performing work tasks.
Wearable technology is one of the latest developments in health care. The Wearable Advanced Sensor Platform (WASP) is a physiologic monitoring system comprised of the Globe® flame-resistant base layer shirt and the Zephyr™ Bioharness 3 technology. The Bioharness is a compact device that captures real-time and recorded information that may be useful for research and fireground operations. It may be worn with the base layer shirt or a chest strap. Coupling this technology with Omnisense software makes it possible for incident commanders to track firefighters’ cardiac and thermal strain.
Live Fire Training Study
In May 2017, the HPFD conducted its biannual mandatory live fire training over a three-day period; all department personnel were included. The live fire training process HPFD used was a planned training exercise that permitted evaluation of the physiological status monitors as part of the overall SMARTER project. The Skidmore College Institutional Review Board approved the study. Approximately 10 to 12 percent of U.S. firefighter fatalities occur during training, and a significant proportion (56 percent) of them are caused by cardiac events.1 Although the cardiovascular strain of firefighting drills has been well documented, the cardiac and thermal strain experienced throughout an entire training day has not been well characterized. Research has shown that live fire training drills can result in cardiac strain of near maximal to maximal heart rate (HR).2-3 Prior research has examined firefighter HR during individual drills or short-term bouts of fire suppression activities.4-5 We are not aware of any research that has specifically focused on the “cleanup” period. Furthermore, little work has been done to compare cardiac strain of fire instructors and students. This live fire training study examined the cardiac strain between firefighters (i.e., students) and instructors and evaluated the physiologic strain during cleanup periods following live-fire training.
Study Protocol
Study personnel wore structural PPE and self-contained breathing apparatus (SCBA) for each of the drills. Work bouts were based on the accomplishment of objectives rather than time limits, as had been studied in the past. Participants wore a WASP-equipped base-layer undershirt or chest strap (physiologic status monitor).
The physiologic status monitor (PSM) continuously recorded participants’ HRs, activity levels, breathing rates, estimated core body temperatures, and single-lead electrocardiogram. The tight-fitting PSM-equipped shirts/chest straps allowed for physiologic data to be collected during the drills. The firefighters powered on their PSMs prior to the first drill and did not turn them off until after the recovery period at the end of the training. At the completion of the training, the data recorded on the PSMs were downloaded for analysis.
Training Components
The training consisted of three live fire drills each day; each drill was designed to simulate the conditions of different fire scenarios. Following each drill, firefighters doffed their helmets, hoods, SCBA, and turnout coats and lowered their bunker pants to allow heat to dissipate from their lower extremities and groin area. They were given a brief rehab period that included partaking of cold fluids and fruit. Following this brief rehab period, they began resetting their equipment and apparatus.
All drills were conducted at a Class A fire training structure/facility operated by the Addison (IL) Fire Protection District. All burns were conducted in accordance with National Fire Protection Association (NFPA) 1403, Standard on Live Fire Training Evolutions, 2012 ed., Chapters 7, 8.6
Drill 1 involved a fire company making a “quick hit” on a Class A transitional attack prop, followed by advancing a hoseline into the training structure to complete extinguishment of fires burning inside “burner props.” These props are specifically designed to simulate fire behavior inside a structure. Materials burning inside the props were restricted to wood pallets and straw. Additional fire companies performed simultaneous coordinated ventilation and victim searches on multiple floors.7
Drill 2 focused on standpipe operations within the multistory structure, including controlled low-rise “outside vent” ventilation and interior searches.
Drill 3 included several objectives revolving around vent-enter-isolate-search (VEIS) while conducting a simultaneous transitional attack followed by advancement inside the structure. Weighted mannequins were used to simulate victims. These mannequins were removed by ladder during the VEIS portion of the drill. (7, 2-3)
Results
Recruit/Rookie Firefighters. These live fire training sessions included a group of several recruit/rookie firefighters who were just beginning employment with the HPFD. This allowed for an interesting comparison between new and experienced firefighters.
All new HPFD personnel are required to meet the base standards of NFPA 1001, Standard for Fire Fighter Professional Qualifications, before they can fully engage as part of an operating company.8 The rookies were still attending their “academy training program” and were thereby restricted in their level of involvement. Despite that the rookies did not directly interact with or enter the immediately dangerous to life or health atmosphere, they displayed the highest peak HRs for each exercise. Similarly, they possessed the highest peak estimated core temperature for all drills and the highest average core body temperature for the transitional attack drills. This suggests that rookies have an exaggerated physiological response caused by their mental state (a heightened sympathetic response).
Experienced Firefighters. The experienced firefighters generally had the highest average HRs and core temperatures. This reflects their level of activity during the training. The drill instructors along with the chief officers filling the “interior chief position” had elevated HRs. The HPFD’s policy is to assign an interior chief whenever three or more companies are operating in the same/general geographical area inside a structure. This allows the company officers to manage their company personnel while the chief officer coordinates operations.9 All groups (firefighters and instructors) worked hard throughout the entire training block, resulting in elevated HRs and core temperatures (Tco). Both firefighters and instructors achieved approximately 100 percent of age-predicted maximal heart rates (APMHR) at some point during the drills. Throughout the training day, the HR mean was ~62 percent of the APMHR.
As detailed in Table 2, firefighters had a higher estimated Tco (peak and average) than the instructors. The differences, however, are minimal and not statistically significant. The firefighters also exhibited a greater HR response when compared with the instructors. Firefighters’ HR peak was 5 beats per minute (bpm) greater than that of the instructors (188 bpm vs. 183 bpm, respectively). Like the differences in Tco, these variations were not statistically significant. The average HR for the entire training cycle was 116 bpm for firefighters compared with 113 bpm for instructors.
When the HR was expressed relative to age (220 − age), firefighters were at 102 percent of their HR peak vs. the instructors at 99 percent of their HR peak. The average firefighter age was 35 years vs. 36 years for instructors. The single time when the instructor’s HR was greater than the firefighters was at the beginning of the training day during the instructional and safety talk (instructors’ HR = 95 bpm, firefighters’ HR = 90 bpm).
During the drills, even the chief officers, who were generally not engaged in heavy physical activity and were focused more on general supervision and company coordination, demonstrated HRs consistently above 100 bpm, with the most extreme HRs reaching near 200 bpm (similar to what would be expected from a high-intensity workout).
After visually reviewing the data and realizing that HR remained elevated following the conclusion of a drill, researchers performed a subanalysis of the training on Day 1 to investigate the physiological work completed during a designated cleanup period—specifically, HR and estimated Tco response. As seen in Table 3, cleanup took approximate 33 minutes; during this time, some of the highest HRs were obtained (173 ± 16 bpm) along with elevated Tco (37.8 ± 0.2°C) even though personnel were not wearing PPE coats, hoods, and helmets.
Table 4 focuses exclusively on cleanup and the physiological data comparison between firefighters and instructors. In this case, HR and estimated Tco are lower in the instructors than in the firefighters. This was expected, as the instructors did far less physical work during cleanup and reset than the firefighters. The instructors provided oversight and coaching, but the firefighters performed the bulk of the work, thereby increasing their overall physiologic strain.
Conclusion and Recommendations
All participants reached APMHR and had a mean HR greater than 60 percent of APMHR throughout the day. There were no statistically significant differences in HR or estimated Tco between instructors and firefighters. We also found that the exertion during cleanup activities is as physically demanding as the live fire drills, resulting in cardiac and thermal strain. When considering the physiologic strain of firefighter training, we must consider the physical work associated with cleanup and be careful not to assume that this period of activity is part of “recovery” from the training drills.
Now that we have a better understanding of the stress imposed during cleanup, officers should proceed cautiously when directing personnel to immediately pick up and prepare for a subsequent response without focusing attention on rehab, including rehydration, core body cooling, rest/recovery, and nourishment. Consider using personnel who were not as heavily engaged in the overall incident workload to assist in pickup and apparatus reset. Additionally, once the apparatus have been reset for the next response, officers need to be keenly aware that their personnel have not yet fully recovered from the physiologic impact of heat stress as they return to quarters or respond to the next incident. The focus should continue to be on hydration, an ordered period of rest, and self-decontamination (shower and change of clothing).
Remember: Equally as important as placing our apparatus back into service is the need to “put the firefighter back into service.” Gaining a better understanding of the physiological strain that results from the challenges of the job is essential in reducing firefighter injuries and line-of-duty deaths. The use of PSM as part of the SMARTER project provided the HPFD with a unique opportunity to better understand a component of our job that we had previously not thought much about.
References
1. Fahy, RF, LeBlanc, PR, Molis, JL. (2015) Firefighter Fatalities in the United States-2014. National Fire Protection Association, 2015. http://www.nfpa.org/.
2. Horn, GP., Blevins, S, Fernhall, B, & Smith, DL. (2013). “Core temperature and heart rate response to repeated bouts of firefighting activities” [Research Study], Ergonomics, 1465-1473.
3. Smith, DL, Manning, TS, & Petruzzello, SJ. (2001). “Effects of strenuous live-fire drills on cardiovascular and psychological responses of recruit firefighters” [Research Study], Ergonomics, 201.
4. Horn, GP, Kesler, RM, & Motl, RW. (2015).” Physiological responses to simulated firefighter exercise protocols in varying environments” [Research Study], Ergonomics.
5. Petuzzello, SJ, Poh, PY, Greenlee, TA, Goldstein, E, Horn, GP, & Smith, DL. (2016). “Physiological, perceptual and psychological response of career versus volunteer firefighters to live-fire training drills” [Research Study], Stress Health.
6. National Fire Protection Association. (2012). NFPA 1403, Standard on Live Fire Training Evolutions [Professional Standard]. Quincy, MA: NFPA.
7. Hanover Park Fire Department-Training Division. (2017). Spring Live Burn Training [Lesson Plan/Drill Chart]. Hanover Park, Illinois, 1.
8. National Fire Protection Association. (2013). NFPA 1001, Standard for Fire Fighter Professional Qualifications [Professional Standard]. Quincy, MA: NFPA.
9. Hanover Park Fire Department. (2017). General Fire Ground Tactical Operations [Standard Operating Procedure]. Village of Hanover Park, Hanover Park, IL: Hanover Park Fire Department.
CRAIG A. HAIGH, a 35-year veteran of the fire service, is chief of the Hanover Park (IL) Fire Department and a field staff instructor with the University of Illinois Fire Service Institute. He is a frequent partner with the University of Illinois Fire Service Institute’s Firefighter Life Safety Research Center and the Skidmore College First Responder Health and Safety Laboratory. He is a published author and a national speaker. He has a BS degree in fire and safety engineering and an MS degree in executive fire service leadership. He is a graduate of the National Fire Academy’s Executive Fire Officer Program, is a nationally certified paramedic and an accredited Chief Fire Officer, and is a member of the Institute of Fire Engineers. He was named the 2012 Illinois Career Fire Chief of the Year.
ANDREA F. WILKINSON is the project manager for the Skidmore College-First Responder Health & Safety Laboratory. Previously, she spent nine years at Alfred University as the head athletic trainer and clinical coordinator for sports medicine. She attended the University of Akron, where she earned dual bachelor of science degrees in sports medicine for athletic training and exercise science as well as a master of science degree in exercise physiology with a concentration in cardiac rehabilitation. In 2008, she was named an honorary member of Outstanding Women in Education and is an alumna of Leadership Lorain County. She has extensive experience in sports medicine and cardiac rehabilitation through her work with St. Peter’s Health Partners in the CVICU. She has a special interest in preventative medicine for the tactical athlete and first responder.
DENISE L. SMITH is professor of health and human physiological sciences at Skidmore College in Saratoga Springs, New York, and a research scientist at the University of Illinois Fire Service Institute. She is director of the Skidmore College-First Responder Health and Safety Laboratory. Her research focus is the physiological effects of firefighting, particularly the cardiovascular strain associated with the combination of heavy physical work and heat stress firefighters routinely encounter. She is the author of Exercise Physiology: For Health Fitness and Performance, which is in its third edition, and of more than 70 scientific peer-reviewed articles. She received the Dr. John Granito Award for Excellence in Fire Service Leadership and Management Research. She earned her Ph.D. in kinesiology with a specialization in exercise physiology from the University of Illinois at Urbana-Champaign. She presents her research and its applications internationally.
LELAND B. HAIGH is a research assistant at Skidmore College-First Responder Health and Safety Laboratory. He began working on the SMARTER project doing data collection as a high-school senior at Wheaton Academy in West Chicago, Illinois. He is pursuing his college education with a focus on science.
