Structural Firefighting: Protecting Against the Hazards of Tunnel Vision

BY DAN HALE

Most firefighters have seen someone with dangerous tunnel vision or have experienced it themselves. When entering a structure fire with a crew or driving fire apparatus to a scene of a confirmed rescue situation, it is completely normal to have extremely focused attention and even physical signs and symptoms of stress and excitement all at once. It is when the focused attention and physical symptoms start negatively affecting the firefighter’s thinking ability and actions that the firefighter or others can be dangerously impacted.

The physical signs of the stress response can be objectively seen in someone. There are also cognitive, emotional, and behavioral effects seen as part of a stress response; they can be more difficult to detect. An unchecked physical stress response will exacerbate cognitive, emotional, and behavioral effects.

When tunnel vision affects situational awareness, lives are affected. Safety and proper thinking can be maintained by understanding how tunnel vision happens, taking preventive actions in high-risk situations, recognizing danger signals, and acting to change the path of events when danger signals appear.

How Tunnel Vision Happens

Tunnel vision is often described as a safety issue, but the precise basis of tunnel vision is not often discussed. Tunnel vision is usually used to describe a situation in which a firefighter has a narrow point of view and is not looking at the “big picture.” In an emergency situation, one dangerous area or situation is usually dominant, and it is not always innate for a person to evaluate other simultaneous situations.

Technically, the original medical meaning of tunnel vision is that objects can only be seen when at the center of vision and other peripheral objects are blurry or cannot be seen at all. Both of these definitions are relevant and interact with each other for firefighting.

The body’s sympathetic nervous system creates and worsens tunnel vision. This system is activated involuntarily in response to stimuli in an effort to prepare the human body for immediate physical action. This reaction is also known as a “fight-or-flight” response. It consists of nerves and hormones such as epinephrine (adrenaline).

The sympathetic reaction can activate multiple areas of the body, including the following:

Heart: increases blood pressure and heart rate.
Lung: opens lower airways to facilitate improved breathing.
Blood vessels: constricts blood vessels to move more blood to the heart.
Food stores: changes stored fat and glucose to immediate energy.
Intestinal tract: slows digestion.
Glands: decreases tear and saliva production.
Eyes: dilates pupils.
Ears: decreases hearing.

This reaction is helpful for short-acting intense situations (e.g., primitive escape responses, fighting, and hunting), but it can be harmful in modern situations involving multiple variables or prolonged conditions.

In a modern environment, such as that of driving fire apparatus to an emergency, some of these responses are counterproductive. For example, dilation of pupils can let more light into the eye but can cause a decrease in peripheral vision, which is also called tunnel vision. Similarly, a decrease in auditory input can help a person to focus on a specific task, but in a situation with a changing environment, such as operating a vehicle or operating the nozzle in a room-and-contents fire, all auditory and visual input is required.

In addition, responding to a fire situation is not a short event. The sequence of the incident can include getting the initial call; putting on gear; driving, or being driven in, apparatus; arriving on scene and performing size-up; preparing for a fireground task; and then actually carrying out those tasks. A volunteer firefighter also has the response time of traveling to the station from home.

The fight-or-flight response is biologically meant to prepare a body for a few short minutes of action. The fire response described above can involve possibly several hours of work. The activation of the sympathetic nervous system with prolonged release of hormones such as epinephrine will cause unwanted stress on the body, which will cause muscle fatigue, loss of energy, and possibly impaired thinking.

If the period of tunnel vision is prolonged, it will worsen the already decreased functioning of the body. In the example of the driver getting the call and responding to the scene, the statistical chance of an accident happening keeps increasing as the driver gets closer to the scene or at the scene itself if this process is unchecked.

Preventing Tunnel Vision

Training and repetition in daily duties can overcome the initial type of tunnel vision described, in which a firefighter focuses only on the task at hand and has diminished situational awareness. For every call, the firefighter must think clearly through every step and step back and analyze all data before every action. For example, drivers must take safety courses so they are aware of driving hazards and then drive the safe, correct way every time. If drivers stop or slow at every intersection on all routine calls, they will also slow or stop at every intersection on the high-stress rescue call.

Similarly, firefighters must stay current on the operation of their breathing apparatus. If they use the breathing apparatus appropriately and regulate air well on routine calls, they will operate breathing apparatus safely and appropriately at more demanding incidents. This “motor memory” will also help offset any diminishment in muscle function that comes from blood vessel constriction when the sympathetic nervous system is activated.

The second type of tunnel vision, which is caused by the fight-or-flight response, can be more difficult to prevent or control. It is expected, and can be helpful, to have the sympathetic nervous system activated briefly by an emergency call. However, when the biological fight-or-flight responses are prolonged, fatigue can set in more quickly and damage the very body systems that were meant to help.

Firefighters must train themselves to balance the sympathetic nervous system. An initial step is to maintain good physical conditioning. The activation of the fight-or-flight response has direct physical effects on the body. Fast breathing, chest tension, and vision changes are normal, even in a young athlete, when this system is activated. The activation of the sympathetic nervous system, which includes increased blood pressure and heart rate, is directly related to the fact that heart attacks are the leading cause of death for firefighters on the job.

Slowing the response and processing speed down will help with maintaining good situational awareness and decreasing activation of the sympathetic nervous system. Small steps, such as taking deep breaths or talking through a plan with a colleague, can keep a firefighter’s mind sharp. This is the reason some police departments have banned high-speed chases and some fire departments limit responses above the speed limit in routine calls: If the driver can decrease activation of the sympathetic nervous system, response times and critical thinking skills can remain intact.

Finally, there is the potential of “stress inoculation training,” which is training safely and correctly under high-stress conditions in an attempt to recreate an emergency situation. Again, if the firefighters train appropriately, they will act safely and slow down on an emergency call.

Recognizing Tunnel Vision and Action

For the classic type of tunnel vision in which firefighters focus only on the task at hand, the firefighters often do not recognize that they have decreased situational awareness. Training, concrete action plans, and standard organizational routines may offer methods for maintaining the big picture or a chance to regroup when a situation changes. At every possible step, firefighters should reanalyze all data.

In addition, firefighters must remember to support each other as an added layer of safety. If a driver is operating at unsafe speeds, the officer must intervene. If a firefighter is low on air or is not sizing up a building safely and is only concentrating on the burn room, the officer or a fellow firefighter must immediately intervene.

Another way to prevent the effects of tunnel vision is to be aware of the signs of the sympathetic reaction listed above. If these changes (elevated heart rate, fast breathing, vision changes, dry mouth) go unchecked, the firefighter will quickly become fatigued and can begin making unsafe decisions. If you notice these changes starting, you must immediately slow down, both mentally and physically. Rethink the current task to stay sharp, slow your breathing, and walk more slowly in an attempt to slow down this body response. If you cannot quickly slow the mind and body, the changes will accelerate, and you will no longer be able to notice that you are operating at an unsafe level. It is imperative that you recognize these signs early, and if you cannot overcome them, take a break or go to the rehab station if appropriate.

Again, firefighters must remember to support each other as an added layer of safety. If an officer or a firefighter notices that someone is having breathing difficulty, is moving slowly, or is not making proper decisions, that officer or firefighter must check in with that firefighter immediately and potentially remove that firefighter from the current duty. The culture of safety should be that it is better to replace the firefighter before the firefighter or someone else becomes injured.

A recent example of preserving situational awareness and saving lives by avoiding tunnel vision occurred in Boise, Idaho, at a three-alarm structure fire. A captain recognized signs of imminent collapse because of failed trusses and bulging exterior walls during a house fire. He radioed incident command, and the incident commander (IC) relayed the message to firefighters in the collapse zone that they should move out of the area. They did so safely, and there were no major injuries. The time between the IC’s relaying of the message and the collapse was only six seconds. Because the captain had good situational awareness and the firefighters were monitoring radio traffic without succumbing to tunnel vision, lives were saved.

Tunnel vision is a common occurrence on the fireground. Normal biological reactions can worsen it. By recognizing how and why tunnel vision happens, you can take steps to diminish the effects of these responses to maintain safety.

References

Meichenbaum, D. (1996). “Stress inoculation training for coping with stressors,” The Clinical Psychologist.

Sherwood, Lauralee (2008). Human Physiology: From Cells to Systems (7 ed.). Cengage Learning.

Gladwell, M. (2005). Blink: The Power of Thinking without Thinking. Back Bay Books, Little, Brown.

Boise (ID) Fire Department news release, 02 August 2013.

DAN HALE is a firefighter and physician. He is a member of the Kittery (ME) Fire Department and is a hospital-based physician at Tufts Medical Center in Boston, Massachusetts. He has a special interest in critical thinking and application to disaster response and everyday emergencies. He is also involved in public education and recently received a national grant to help install smoke and carbon monoxide detectors in underserved homes.