Chapter 10

Chapter 10

Reading Firefighters

Objectives

• List the three factors that lead to overexertion, the three ergonomic factors that can produce injury, and the three strategies to mitigate ergonomic hazards

• List the three factors that impact human cell performance, explain its chemistry, and define fuel replacement strategies to increase it

Objectives (con’t.)

• Discuss the two types of thermal stress

• Explain the role of hydration in preventing injuries

• Define the four Rs of firefighter rehabilitation

Reading Firefighters – Is It Possible?

• Human performance depends on many factors

• Overexertion is the leading cause of injuries (and deaths) at incidents

• Reading firefighters involves the evaluation of factors that lead to overexertion– Fire service has actually set up firefighters to

be injured

Reading Firefighters – Is It Possible? (con’t.)

• The overexertion setup– Firefighters are the only professional athletes

who work at peak performance without warm up• Physical and mental challenges are required at a

moment’s notice when an incident occurs• Essence of fire service professionalism: the ability to

function safely at all times• Solution: address physical and mental demands of

firefighters

Reading Firefighters – Is It Possible? (con’t.)

• Overexertion resistance– Firefighters should be physically fit to resist

overexertion and injury• Proactively aim for strength, flexibility, and aerobic

fitness• Adopt program for efficient fueling for their

metabolism• Know how their bodies respond to stress

Figure 10-1 The physically fit firefighter can resist overexertion longer with minimal injury risk.

Reading Firefighters – Is It Possible? (con’t.)

• Overexertion realities– ISOs must deal with “here-and-now”

overexertion threats regardless of firefighters’ preventive fitness efforts

– ISOs can address human overexertion factors• Ergonomics• Physiology• Rehab efforts

Ergonomics

• The science of adapting work or work conditions to a worker

• The study of problems associated with people adjusting to their work environment

• A firefighter’s workplace includes the fire station, apparatus, and the incident scene

Figure 10-2 Firefighters seldom find an “ergonomically friendly” workplace.

Ergonomics (con’t.)

• Ergonomic stressors– The physical environment

• Surface conditions, temperature variations, lighting, equipment, etc.

– Relationship of the worker to the environment• Bending, ascending or descending, pushing, etc.

– Task being attempted • Energy and amount of focus required• Task priority and number of people

Ergonomics (con’t.)

• Ergonomic abatement strategies– Awareness

• Warnings and reminders

– Accommodation• Altering environment, task, or personnel

– Acclimation• Usually done proactively• Fitness programs, prehydration, stretching exercises

prior to assignment

Firefighter Physiology

• Physiological performance depends on metabolic processing (cell chemistry) of firefighter

• Factors that affect cell chemistry– Thermal stress– Hydration– Fuel replacement

Firefighter Physiology (con’t.)

• Thermal stress– Heat stress can be caused by:

• Activity• Humidity• Air temperature• Reduced effectiveness of cooling mechanisms (i.e.,

PPE)• Sun, shade, and wind

Figure 10-3 The ISO should be observant of the signs and symptoms of heat stress.

Firefighter Physiology (con’t.)

• Thermal stress (con’t.)– Heat stress reduction

• Passive cooling: use of shade, air movement, and rest to bring down core temperatures

• Active cooling: uses external methods or devices to reduce body core temperatures

• Temperatures above 101 degrees Fahrenheit should trigger active cooling

Firefighter Physiology (con’t.)

• Thermal stress (con’t.)– Cold stress can be caused by:

• Moisture (perspiration)• Immediate temperature change• Wind chill• Level of activity• Duration and degree of exposure

Figure 10-4 Hypothermia is the cooling of the body’s core temperature, a condition that should be avoided at all cost.

Firefighter Physiology (con’t.)

• Fighting thermal stress– Accommodation

• Warm clothing cold extremes• Forearm cold water submersion for heat extremes

– Rotation• Planned action to rotate crews

– Hydration• Important in both heat and cold stress environments

Firefighter Physiology (con’t.)

• Hydration– Firefighters should drink a quart of water an

hour during work periods• Best delivered in 8-ounce increments spread over

the hour

– For activities longer than an hour, add essential electrolytes and nutrients to water

• Dilute sports drinks with 50 percent water to speed absorption

Firefighter Physiology (con’t.)

• Fuel replacement– Metabolic rates are influenced by:

• Lifestyles• Fitness• Illnesses• Over-the-counter and prescription drugs• Circadian rhythms: physiological response to the 24-

hour clock, which includes sleep, energy peaks, and necessary body functions

Firefighter Physiology (con’t.)

• Fuel replacement (con’t.)– Cell theory

• Optimal cell performance uses oxygen, water, glucose (food), and insulin

• Too much insulin in the system tells the body to store carbs, not use them

• Fuel firefighters with a low-glycemic index food so that blood sugar levels and insulin are stable, gradual, and consistent

Table 10-2 Glycemic index comparisons for common carbohydrates.

Firefighter Physiology (con’t.)

• Fuel replacement (con’t.)– Cell-fueling strategy

• 40/30/30 balance of low glycemic carbohydrates, protein, and fat provides quick energy that optimizes cell performance

• Choosing the best protein, carbohydrate, and fat also promotes steady, sustained performance

• Department should preplan nourishment for rehab

Firefighter Physiology (con’t.)

• Fuel replacement (con’t.)– Eating cycle at incidents

• Feed now if more than two hours since the last food intake

• Feed every two to three hours when physical and mental demands remain

Rehabilitation Efforts

• ISO functions– Ensure IC has established a rehabilitation

tactical management component during emergency operations

– Evaluate rehab efforts to determine effectiveness

Rehabilitation Efforts (con’t.)

• The Four Rs of Rehab– Rest– Rehydration– Rx– Refueling

Summary• Most firefighter mistakes/injuries are due to

overexertion• Ergonomic stressors

– Physical environment– Relationship of worker to environment– Task being performed

• Abatement strategies for ergonomic stressors– Awareness, accommodation, and acclimation

Summary (con’t.)

• Physiological stressors are influenced by:– Thermal stressors

• Hot or cold• Abatement: crew rotation, accommodation, and

hydration

– Hydration– Fuel replacement

Summary (con’t.)

• Optimal human performance relies on optimal cell performance– Balance food intake– Eat in regular cycles

• Evaluate rehab efforts– Ensure the four R’s are implemented and

achieving results