Incident commanders must recognize the limitations that their troops face while operating in high heat and humidity conditions. Firefighters are often physically spent after only 10 to 15 minutes when the THI (temperature-humidity index) exceeds 90. Additional assistance will be required if the fire is not immediately controlled. The need for reinforcements should be planned for as soon as a working fire is encountered when the THI exceeds 90. If fresh troops are not needed for fire control, they can relieve the troops who knocked the fire down, performing overhaul.
In some cases, getting reinforcements may require the transmission of multiple alarms or calling mutual aid. Some chiefs are reluctant to call for these alarms for fear they will be perceived as weak, that "they can't handle a fire without help." That's nonsense! Such requests for assistance should be taken as a sign that the officer is looking out for the welfare of his or her firefighters as well as the welfare of the community. Weary firefighters make mistakes and move slower and get injured at a higher rate than do fresh personnel. The relief of firefighters has contributed to a decline in the number of members on medical leave.
Relief and rotation of personnel has other benefits. Overhaul is accomplished more quickly, with less resulting incidental damage, and additional people get an opportunity to sharpen their skills. In recent years, there has been a nationwide trend toward fewer and fewer fires and thus less hands-on experience for firefighters. Rotating crews can help expose more personnel to each incident.
Of course, relief of personnel is not strictly a summer problem. Fires in cellars, sub-cellars and high-rise buildings are common examples of incidents which routinely require rotation and relief of companies, even in the dead of winter. This is largely due to the degree of confinement and the use of large quantities of steel and concrete, radiating heat back at attack crews. Under these oven-like conditions crews often need relief every five minutes to avoid baking within their protective clothing.
High-rises have the additional problem of fatigue. When elevators are unsafe or unusable, attack crews must walk up many flights before they can go to work. At a recent high-rise multiple-alarm fire, my unit climbed up more than 30 flights of stairs, forced many doors, searched dozens of apartments, opened walls and ceilings, and did all the other required tasks for nearly three hours. During a slight respite, we were told by our sector commander to go up several more floors to check out a report of yet another involved apartment with people trapped. Only after we reached this floor and found that our services were not required (other units had gotten there first) did we assess our physical condition. It was terrible. We were vastly overextended.
In the heat of a serious firefight, the involved crews are often not the best judges of their physical stamina. The heart and mind are willing, but the body is saying, "No mas, no mas." That is why safety officers as well as incident and sector commanders must be alert to what tasks the units under their command have been performing, and be prepared to provide them with relief in a timely fashion.
What constitutes timely relief varies from incident to incident. For "routine" structural firefighting, personnel should be relieved after two 30-minute air cylinders have been expended, or about 45 minutes if no self-contained breathing apparatus (SCBA) use is required. This, of course, requires that sufficient personnel be on hand to replace those relieved. If no additional people are on hand, the original units will have to continue to operate but this will take its toll. Fire will extend while people move slower.
If wholesale relief of units is not possible under these circumstances, then personnel should each receive medical screening as they exchange air cylinders. Pulse rate, blood pressure, respiration and body temperature should be evaluated. Pre-established criteria should permit medical personnel to relieve firefighters whose vital signs are outside the range of norms for people of their age groups after exertion. Tables of such data are available from many physicians.
Firefighters can and should reduce the effects of heat stress on themselves by taking a number of actions, some before the incident, others during and after. Firefighting is a serious physical challenge requiring its participants to be in good physical condition. Aerobic training is most beneficial, coupled with exercises that utilize the muscle groups firefighters use most often, notably legs (stair climbing) and upper body (pulling ceilings, advancing hoselines and carrying victims).
Each member must maintain optimum hydration (body fluid level) before the incident, as well as during and after. Firefighters should consume several glasses of water each day, more during warm weather. This should be done before the incident, regardless of thirst level. Thirst is a poor indicator of your hydration level; by the time you feel thirsty, you could be seriously dehydrated.
During an incident, a firefighter must take several additional steps. As soon as the fire is knocked down and their use is no longer needed, remove protective hoods and raise helmet earflaps to begin venting body heat. The head dissipates a large portion of this heat. As soon as possible upon reaching an area where it is safe to do so, open up the coat and bunker pants flaps. Remove the coat, pants and helmet entirely as quickly as you can if it is safe to do so. Cool water applied to the head and neck provides essential cooling for the most vital temperature sensitive organ in the body the brain. Immediately begin replacing body fluids lost through sweat. Water is very good for this, better than many other beverages, in fact.
Many departments have established rehabilitation units that respond to working fires and other incidents. Many of the functions these units perform can be improvised on the fireground. The area selected for rehab must be safe for firefighters to remove protective clothing. Any shady spot will do.
Air movement tremendously im-proves cooling. Fans that vent a building also can cool firefighters. A water mist adds to the cooling effect. A section of garden hose of the type with tiny holes punched along its length can be placed downwind of a fan to provide rapid cooling. This arrangement must be used with care; personnel can rapidly get quite wet. They must not be permitted to re-enter a high-heat environment until they are dry. Otherwise, they are likely to suffer steam burns under their protective clothing.
John Norman, a Firehouse® contributing editor, is a captain with the FDNY, assigned to Rescue Company 1 in Manhattan. He is also an instructor at the Nassau County, NY, Fire Service Academy and lectures nationally on fire and rescue topics. Norman is the author of Fire Officer's Handbook of Tactics, which may be ordered by calling 800-752-9768.
