EMS Emergency Incident Rehabilitation

Issues of Concern

Most work-related injuries among firefighters are minor, with muscle pain, strains, or sprains accounting for 46% of fire ground injuries.  Wounds, bleeding or bruising, cause approximately 14% of injuries. In a 2016 study, smoke or gas inhalation accounted for 8% of fire ground injuries, and thermal stress or exposure (frostbite, heat exhaustion) caused 7% of injuries.

As firefighting became professionalized during the 1970s and 1980s, firefighter related deaths declined significantly. While the overall number of injuries among firefighters responding to incidents has decreased over the past 30 years, and the number of fires has also declined; overall, the rate of fire ground related injuries have been relatively stable. The number of firefighter deaths has been relatively stable, with a slight decrease in the past ten years.[1]  In 2019, over half of all firefighter deaths were attributed to overexertion, stress, and medical issues.  Over the past 10 years, Sudden cardiac death has accounted for over 42% of all firefighter deaths while on duty.[2][3]  Stress and overexertion were the cause of over 98% of all United State firefighter cardiac-related fatalities from 2002 through 2012.[3] 

Clinical Significance

Indications for Fire Rehabilitation

Formal fire rehabilitation procedures are necessary for firefighters who have been involved in incidents requiring significant exertion or where there is a significant risk of injury, exposure, or stress. Most structure fires or wildland fires responders will need some type of rehab operations.  Training exercises and large events requiring responses, or standbys, may also require rehab operations.

Establishing Fire Rehabilitation Operations

The scale and scope of fire rehabilitation operations will vary depending on the type and size of the incident. Rehab operations should have dedicated staff explicitly focused on rehab, separate from firefighting responsibilities. NPFA 1584 describes the need for a dedicated rehab manager, who ensures adequate food and hydration for responders, accountability of all personnel (with appropriate record-keeping), and the release of individuals needing additional medical care to EMS. While resource-limited settings may necessitate the same personnel to provide both rehab oversight and for the transport of firefighters requiring a higher level of care, this should be avoided since the practice can lead to interruptions in care and documentation of rehab operations.

NFPA 1584 recommends that EMT-Basics, at a minimum, should be available for fire rehab. Rehab personnel should have access to at least basic first aid supplies, monitoring equipment, and an automated external defibrillator.

Rehab Surveillance, Screening & Treatments

NFPA 1584 makes specific recommendations for the minimum frequency and duration of rehab: 

• “Rehabilitation following the use of a second 30-minute or 45-minute self-contained breathing apparatus (SCBA) cylinder, a single 60-minute SCBA cylinder, or 40 minutes of intense work without SCBA."
• "Members entering rehabilitation for the first time shall rest for a minimum of 10 minutes and longer where practical."
• "Members shall rest for a minimum of 20 minutes following the use of a second 30-minute or 45-minute self-contained breathing apparatus (SCBA) cylinder, a single 60-minute SCMA cylinder, or 40 minutes of intense work without a SCBA."

These guidelines, based on the use of SCBA use, were not based on the medically optimal duration of exertion, but rather convenience, as firefighters generally keep track of time based on SCBAs use. 

NFPA 1584 suggests that checking vital signs in rehab (temperature, heart rate, respiratory rate, blood pressure, oxygen saturation, and carboxyhemoglobin level in cases of possible smoke exposure) is necessary. Per NFPA 1584guidelines, firefighters with a heart rate of over 100 beats per minute or blood pressure over 160/100 mm Hg after 20 minutes of rehab should not return to activity. There is little data on the implications of these cut-offs, but the most extensive retrospective study of these guidelines showed that about half of firefighters entered rehab with a heart rate over 100, and a small minority of firefighters fell outside recommended blood pressure parameters. Only half of those entering rehab had their vital signs re-checked.[4]

A study of blood pressures during heavy exertion while in a hot environment, and subsequent rehab, found that post-exercise hypotension is more common during rehab than significant or persistent hypertension.[5]  

Facilities used for fire rehab may vary by region, climate, type of incident, and length of response. Small, brief rehab interventions may require little more than rehydration be made available to firefighters. Larger incidents or prolonged events will likely require the establishment of a formal rehab area close to the incident but separated sufficiently to be free of smoke, excess heat, or media covering the event. Some fire services have dedicated rehab vehicles, with fans, sun protection, and active cooling measures, including misters or proprietary devices that cool all or part of the body.  The use of these colling devices is based on research demonstrating more effective cooling and tolerance of extended periods of exertion in hot, humid conditions when active cooling measures are employed.  Forearm immersion in cool water has been shown to provide greater temperature improvement than a cool-mist (although subsequent research has challenged this conclusion).[6][7]. Longer event responses may require food or provisions, which can be accomplished easily with pre-packaged food or larger scale food preparation.

Fire rehabilitation protocols tend to focus on problems more commonly found in ground fires than in other environments. There should be ongoing surveillance for myocardial infarction, heat exhaustion and stroke, dehydration, hypothermia, carbon monoxide poisoning, and cyanide poisoning.  The rapid triage, treatment, and transport of firefighters with concerning symptoms is important.

Goals of Firefighter Rehabilitation

The goals of fire rehabilitation are:

• To evaluate firefighters for potential illness or injury related to their activities
• To facilitate recovery from fatigue, fluid loss, calorie depletion, and alterations in body homeostasis related to exertion and exposure
• To provide initial stabilization for treatable problems in the field
• To facilitate transport to the closest medical facility if needed

While the focus of this article is on fire rehabilitation areas, staff, and procedures, it is important to remember the need for firefighters to monitor each other for concerning signs or symptoms requiring medical attention. Screening of firefighters for medical evaluation should not be limited to formal rehab operations and personnel.

Heat-Related Injuries

There are several risk factors for heat exhaustion and stroke. Exposure to very high temperatures near fires is an obvious risk factor, but it is vital to consider that heatstroke can be the result of hyperthermia from vigorous exertion, high environmental temperature, or humidity far from a fire.  Temperatures can reach 1,500 degrees Fahrenheit during flash-overs or backdrafts in structure fires, and chemical fires can produce even higher temperatures. Prolonged exposure to high temperatures, especially in full protective gear and during training, can pose a significant risk or even death. 

The U.S. Army uses the acronym HEAT to outline risk factors for heat illness:

• High heat conditions: both high environmental heat and humidity contribute to risk. NFPA does not have a defined temperature or heat stress index above which rehab operations is a requirement, although the U.S. Fire Administration recommends initiating operations when the heat stress index (which accounts for both heat and humidity) is above 90 degrees F or the wind chill index is below 10 degrees F.
• Exertion: Extreme exertion, even if relatively brief, can significantly increase temperature.
• Acclimatization: Humans adapt over time to higher temperatures, with greater sweating, slower metabolism, and greater peripheral blood flow to facilitate cooling.
• Time: The above factors are cumulative. The risk of heat illness increases with more prolonged exposure to high temperatures and extended periods of exertion.

Heat exhaustion characteristically presents with fatigue, lightheadedness, weakness, or dizziness. Heatstroke is a more severe condition marked by severe neurological abnormalities, such as altered mental status, and more significant hyperthermia.[8] While temperature measurements can be helpful in identifying heat-related illnesses in the field, temporal, tympanic, and oral temperature measurements may be inaccurate and incorrectly measure core body temperature.[9][10] Firefighters who are at risk or whom exhibit symptoms of heat exhaustion or heat stroke should be cooled and transported regardless of the temperature measured in the field.

There are multiple factors that can affect a firefighter’s risk of heat-related illness. Dehydration and salt depletion can significantly affect core temperature and response to heat. Excess body weight or poor conditioning can also make firefighters more susceptible to heat-related illnesses.[11] Rashes, sunburns, and other skin conditions can affect the transfer of heat from the skin. Chronic illnesses, such as diabetes and CHF, and acute conditions, such as fever inducing infections, can increase a firefighter’s risk. Older age has also been shown to increase the risk of heat illness. Medications, such as antihistamines and tricyclic antidepressants (that decrease sweating), diuretics (cause dehydration and salt depletion), ephedrine and amphetamines (increase heat production), and lithium (lead to water loss) can affect thermoregulation and the ability to tolerate hot conditions. Turnout gear interferes with the body’s ability to cool, thus firefighters should remove protective clothing during rehab.

Heat exhaustion can be exacerbated by dehydration.[12]  There are numerous studies that show the effect of dehydration on cognitive function, exercise tolerance, and heat tolerance.  Assessment of firefighters during training exercises has shown that the participant's hydration status (based on urine specific gravity) was often suboptimal (over half of study subjects were dehydrated) prior to the start of firefighting activities.[13]  During simulated firefighting activities, the majority of firefighters can lose over 1% of body weight in fluid loss, enough to affect mental function, strength, and dexterity.  The triggering of thirst may not occur until fluid losses are greater than 2% of body weight - which, secondary to decreased skin blood flow and sweating, can increase core body temperature by 0.2-0.4 degrees C. It is necessary for firefighters to initiate rehydration regularly, before they develop the sensation of thirst, to prevent significant dehydration and heat exhaustion. Over a liter per hour of water can be lost during exertion in hot environments. Firefighters should drink at least 2 to 4 ounces of fluids every 20 minutes during firefighting or training activities.

Cold-Related Injuries

Firefighters are also at risk of cold, damp, and freezing conditions, placing them at risk of chilblains, trench foot, frostbite, and hypothermia.

Accidental hypothermia is a drop in core body temperature below 35 degrees Celsius. Patients typically shiver when cold, down to a body temperature of around 32 degrees Celsius.  Below 32 degrees Celcius, shivering stops and patients can develop altered mental status, atrial fibrillation, and can have J waves present on EKG.  Unconsciousness usually accompanies a core temperature below 28 degrees. Care should be taken to move hypothermic patients gently as there are reports of significantly hypothermic patients developing ventricular arrhythmias with normal jostling movements.

ACLS protocols and recommendations should be followed for hypothermic patients with no palpable pulse.  Ventricular arrhythmias may be refractory to defibrillation in hypothermic patients, although this is somewhat controversial. An initial attempt at defibrillation is recommended for hypothermic patients with a shockable rhythm.  The use of vasopressors during resuscitation of the hemodynamically unstable hypothermic patient is recommended by AHA guidelines, though is controversial.[14]

Rewarming is the cornerstone of treatment for hypothermia; this can involve active external rewarming, infusion of warmed saline, forced air rewarming for ventilated patients, gastric and bladder lavage, peritoneal lavage, thoracic lavage, endovascular rewarming, ECMO, or cardiac bypass. Aggressive rewarming of a significantly hypothermic patient requires transport for treatment and invasive measures.[15]

Risk of Carbon Monoxide Poisoning

High carbon monoxide levels, in addition to high temperature and oxygen deprivation, can be an imminent threat to life in structure fires.[16] Symptoms of carbon monoxide toxicity include headache, dizziness, nausea, confusion, altered mental status, and shortness of breath.[17] NFPA guidelines state, “Any firefighter exposed to CO or presenting with headache, nausea, shortness of breath, or gastrointestinal symptoms at an incident where CO is present should be assessed for carbon monoxide poisoning.”

Treatment for carbon monoxide poisoning primarily consists of 100% oxygen. Studies of hyperbaric oxygen treatment have produced variable results.[18]

Multiple other toxins are present during structure fires, including acrolein, formaldehyde, glutaraldehyde, and hydrogen cyanide.[19]  These gases are often present at dangerous levels even after the fire appears to have burned out, during “knock down” operations.[20]  Loss of consciousness in a fire is suggestive of a significant inhalational injury.[21] 

Myocardial Infarction

Firefighters have a disproportionately high rate of workplace-related myocardial events, with over 40% of firefighter deaths while on duty attributed to cardiovascular events vs. 15% of all deaths that occur at work. Fire suppression activities appear to carry exceptionally high risks. While only 1% to 5% of firefighters’ time is spent actively fighting fires, at least 29% of cardiovascular deaths among firefighters occur during active fire suppression.[3] The odds of dying are higher while performing any emergency duties although the highest risk activity is fire suppression.  Physical training can also be a relatively high-risk activity for firefighters.[22]

Firefighters share the same risk factors for cardiovascular events as the general population. Firefighters who die from cardiovascular events are older, more likely to smoke, have more cardiovascular risk factors, and are more likely to have known coronary heart disease than other firefighters.  Most U.S. firefighters who died of cardiovascular events between 1996 and 2002 had not undergone a fire department medical examination in the two years before their deaths.[23]  Most cardiovascular events among firefighters occur in people with modifiable risk factors.  To help minimize risk, it is important for firefighters to obtain routine checkups and medical screening.

Researchers have proposed multiple explanations for the increased risk of cardiovascular events among active firefighters. Oxygen depletion, carbon monoxide toxicity, physical exertion, and emotional stress all likely play a role in the risk of MI.

Diagnosis of myocardial infarction can be complicated in the field as many firefighters actively involved in fire suppression have EKG changes suggestive of ischemia.[24]   There are also many potential non-cardiac causes of chest pain during fire suppression activities, including musculoskeletal pain and inhalation injury.  However, a firefighter with chest pain or anginal symptoms should be treated according to local EMS protocols for a suspected cardiac event and transported to an Emergency Department for further evaluation.