Common Firefighting Hazards: Extreme Heat

There are many commonalities in firefighting across the nation and across the world: firefighters must know how to operate the equipment they use, they should be experts in fire suppression and scene safety, they should also work well with their own crew and any others that arrive on incident scenes. There many more commonalities and they are regularly addressed through firefighter training articles of all kinds. Bottom line, firefighters world-wide have more commonalities than differences. However, there are differences. Some of these differences stem from the employment status of the members of a department: whether they are career or volunteer. Some differences come from the wealth of a locality, which could affect the level of staffing or training available to firefighters. These are types of differences that could potentially be changed through policy, funding initiatives, or the ingenuity for which firefighters are known. Then there are differences between areas that cannot or will not be changed at all. These differences can cause hazards and are due to geographic features, weather, building construction styles, and industry. These articles will focus on what these firefighting challenges are, how to prepare for them, and what impact they have on operations. Summer is here, so let’s dive right into the hazard of heat and humidity.

Firefighting in the Hottest Cities in the U.S.

Obviously, summer isn’t located in just one part of the country. Heat advisories can occur in many locations. However, there are certain geographic areas where the combination of high heat and high humidity for many months of the year increase the risk of the health hazards of heat exhaustion and heat stroke for even the most fit firefighters. The following ten locations are cities that see triple digit temperatures for weeks at a time: Phoenix, Arizona; Las Vegas, Nevada; Tucson, Arizona; Riverside, California; San Antonio, Texas; Miami, Florida; Houston, Texas; Fresno, California; Dallas, Texas; Orlando, Florida.¹ Fire departments operating in these areas and in the surrounding localities work in extreme heat regularly. Additionally, when the temperatures are not 100° or above, they are often in the 90s with high humidity in locations close to the coasts. Departments that regularly operate and train in these hazardous conditions often have specific policies in place to protect firefighters and recruits from injury. Even if a department has not yet developed a formal policy, there are often “unwritten rules” in place such as training only in the early morning or after the sun sets and staying inside as much as possible during the day.

Is Summer Truly a Firefighting Hazard?

Although preventive measures such as staying inside during the hottest part of the day seem intuitive, all departments do not voluntarily change their daily routines and training schedules based on the weather. Firefighting is a “get it done now” type of business. Whether the task is routine or urgent, no one in this field likes putting work on the back burner, so to speak. When operating on an emergency scene, it is even more difficult to keep an invisible hazard, such as heat stress, at the top of the priority list. Few firefighters want to take a break in the middle of a job. However, heat related emergencies are a critical firefighter health and safety survival issue. According to the U.S. Fire Administration², firefighters already work in high-heat environments wearing personal protective equipment (PPE) that creates an added high-heat burden. Environmental heat adds to heat stress; this can cause heat exhaustion and heat stroke, which is often fatal⁴. Fatalities occur because cumulative heat-stress has a negative effect on the cardiovascular system. Recent studies³ have shown that firefighters who operate in high-heat conditions, wear PPE, and are dehydrated—which is not always obvious—can experience vascular stiffness, increased cardiac strain, and decreased perfusion. This suggests a direct link to heat stress and the leading cause of firefighter line of duty deaths: cardiac arrests¹.

How Hot is It?

There are ways to measure heat and humidity but they don’t necessarily show the additive effect of high-heat stress, high humidity, PPE, and physical activity on a firefighter’s health. To more accurately gauge the health and safety risk to firefighters, many departments have begun to use the military developed flag conditions based on the Wet Bulb Globe Temperature (WBGT) Index to determine the appropriateness of training activities and optional operational activities during the summer months. This system can also be used for awareness to guide rehab policies and procedures on incident scenes.

The WBTG Index measures heat stress in direct sunlight while also calculating cloud cover, wind speed, sun angle, humidity, and temperature. It is much more accurate than the heat index, which only calculates temperature and humidity in a shady environment⁵. The flag conditions, which are color coded in green, yellow, red, and black, determine how long and under what conditions strenuous activities may safely be performed outdoors. One important addition the flag index accounts for is PPE. If a person is wearing PPE, 10 points are added to the WBTG number. This basically bumps any flag condition at least two levels. For example, when firefighters are operating under a green flag with a WBTG of 83, if they are wearing PPE, it moves them up to 93, which puts them in the black flag range⁶. Under a black flag, physical training and strenuous exercise should be suspended for all members. It is not possible to suspend firefighting operations or other emergency operational incidents because of a black flag. However, all training and non-mandatory commitments should be rescheduled or held indoors if possible. To continue with “business as usual” under black flag conditions creates a significant risk to the health of firefighters.

Safety Solutions

The changing of the seasons is the only real respite from these extremes of temperature for many areas of the country. However, there are strategies departments can use to prevent significant firefighter injury and death from high-heat stress.

Perform regular fitness testing: The U.S. Fire Administration² has found physically fit firefighters, though not immune from heat-related injuries, are less likely to suffer cardiac arrest. Testing can also discover health issues that require intervention in order to safely perform firefighting duties.
Acclimate firefighters gradually to the heat: Allowing time for firefighters to adjust to the heat can prevent injuries if done in a systematic way. According to Chief Horvath of the Tubac Fire District in Tubac, Arizona, firefighters start training for the heat in early April by holding training drills during the warmer parts of the day to allow their bodies time to adjust to elevating heat conditions.
Ramp up Rehab: Regardless of the size of the department or the formality of the policies, rehab should be in place on incident scenes and during any training while under flag conditions. This rehab should include medical monitoring, hydration stations, and cooling stations where PPE is removed to allow the body to recover.
Request additional assistance early: Large departments should be prepared to dispatch additional personnel to incident scenes due to the decreased operational time and increased rehab time required by on scene personnel. Dispatching additional medical personnel should also be considered. Smaller departments with more limited resources can request that mutual aid respond to the scene to assist with suppression, rehab, or additional medical needs⁷.

Firefighting hazards are everywhere: some are obvious, like smoke inhalation, but some can sneak up on you. Heat injuries from cumulative high-heat stress situations is one of those hazards. Protect your crews this summer through preparation, knowledge, and action!

REFERENCES

Mandy George is a retired lieutenant in the Chesapeake (VA) Fire Department. She has a master’s degree in emergency and disaster management, a master’s degree in professional writing, and an associate’s degree in emergency medical services. She is also a Nationally Registered Paramedic (NRP) and a Virginia Office of Emergency Medical Services (VAOEMS) Education Coordinator.