Did you sleep well last night? If not, you may be at risk for more than just a bad mood. Like good nutrition and exercise, sleep is essential to mental and physical well-being. Chronic lack of sleep impairs performance, contributes to serious health problems, and may even shorten life- span. In an age of increased emphasis on firefighter health and safety, the importance of sleep should not be minimized.

Respondents to the National Sleep Foundation's 2002 Sleep in America poll expressed concerns about work schedules for people entrusted with public health and safety. Eighty-two percent agreed that employees should not be required to work beyond a regular shift if they are too tired or sleepy. Although the survey specifically addressed physicians, nurses, and police officers, it is easy to see how this would apply to firefighters as well.

Firefighters respond to emergencies 24 hours a day and are not immune to the mental and physical consequences of sleep deprivation. Extended periods without sleep, interrupted sleep, and working against the body's natural sleep/wake cycle negatively impact performance and contribute to workplace accidents. Employers can be held liable for accidents involving their sleep-deprived workers. Although you cannot avoid 24-hour operations, you can manage them to minimize their effects on firefighter health and safety.


Sleep, like food, oxygen, and water, is an essential biological need. It reenergizes the body and allows the brain to store and reorganize information. Studies show that performance of newly learned skills does not improve until a person has had at least six—and preferably eight—hours of sleep. During sleep, the body secretes hormones that affect growth, metabolic, and endocrine functions. Activity in the "sleeping" brain helps regulate gastrointestinal, cardiovascular, and immune functions.

The sleep/wake cycle is part of the body's natural circadian rhythms (from the Latin circa "around" and diem "day"). While the circadian rhythm can be affected by exposure to light, it is primarily governed by an internal clock. Located in the hypothalamus of the brain, this genetically programmed mechanism controls rhythms of alertness, body temperature, and hormone production over a 24-hour cycle. Circadian rhythms direct humans to sleep at night and be awake during the day. All living beings, including plants and single cells, follow some sort of natural circadian rhythm.

Circadian rhythms differ slightly from person to person. General-ly speaking, most people experience peaks of energy and alertness in the mid-morning hours and again during late afternoon and early evening. Two periods of decreased alertness and increased sleepiness occur in the early afternoon and at night, with the hours between 1 a.m. and 4 a.m. being the sleepiest. There are inborn preferences for some people to go to bed early and rise early, while others stay up late and get up late.

Every person needs a different amount of sleep to awaken feeling refreshed. Individual sleep requirements are genetic and may be hereditary. Scientists consider six to 10 hours of sleep a normal range, with most people requiring 7.5 to 8.5 hours of sleep in a 24-hour period. At least four to five hours of uninterrupted core sleep is necessary to maintain minimum performance levels. Sleep requirements may change slightly with age and can be affected by general health. Illness, stress, and depression cause the body to require more sleep to heal and recuperate.

Sleep progresses through four distinct stages and a phase known as rapid eye movement (REM).


  • Stage 1: A relaxed, semiconscious state in which a person may be vaguely aware of his or her surroundings.
  • Stage 2: The actual beginning of sleep.
  • Stages 3 and 4: Deeper sleep, during which body temperature drops; metabolic activity slows; and hormones responsible for growth, development, and tissue repair are secreted.
  • Stage 4: The deepest phase of sleep, when the body recovers and heals.


Sleep then moves into the REM phase. During REM, the eyes move rapidly, breathing and heart rates become irregular, blood pressure fluctuates, and muscles become virtually paralyzed. REM plays a major role in memory storage and retention, new learning, and mental performance. It is also the stage of sleep where the most dreaming occurs. At the end of REM, sleep progresses back to the lighter stages of sleep, and the sequence begins again.

Sleep cycles last approximately 90 to 100 minutes and may repeat four to five times a night. If sleep patterns are interrupted too many times, a person will awaken feeling tired. A person's level of alertness depends on the stage of sleep he was in when awakened. In Stage 1 or 2, the person is more likely to wake up feeling alert and refreshed. If he is roused during REM, he more easily remembers his dreams. But if he is awakened from Stage 3 or 4, he may experience sleep inertia, a state of confusion, and diminished performance experienced on waking suddenly from a deep sleep or a nap.


Sleep deprivation occurs when a person does not get sufficient amounts of quality sleep and/or experiences a circadian rhythm disturbance. Work demands, family life, and lifestyle choices may cause a person to sleep fewer hours than his body needs to maintain wakefulness and energy levels. Shift workers and night workers toil and sleep contrary to the body's natural wake/sleep cycle. Some medical conditions or medications may affect a person's quality of sleep. Sleep disorders such as sleep apnea, insomnia, and narcolepsy also contribute to the problem of sleep deprivation.

In today's fast-paced world, sleep is frequently regarded as a luxury instead of a necessity. People view it as a commodity that can be sacrificed for money and lifestyle. Those who sleep less are considered ambitious, hard working, and tough. Unfortunately, this attitude contributes to a lethargic society.

The National Sleep Foundation's 2002 Sleep in America poll found that one-third of the people in the United States regularly sleep 6.5 hours or less per night, short of the 7.5 to 8 hours recommended by scientists and researchers. Studies have proved that decreasing sleep time by one hour a night for seven consecutive nights is equal to staying up for 24 hours straight once a week. Lack of sleep results in drowsiness, fatigue, decreased alertness, slowed reaction times, and impaired thinking and judgment. In fact, recent studies show that being awake for 18 hours produces impairment equal to a blood alcohol concentration (BAC) of .05 and reaches a BAC equivalent of .10 after 24 hours of wakefulness. Thus, a drowsy driver may be as dangerous as a drunk driver and may be so tired that he does not recognize the onset of sleep.


If you feel alert throughout the day and can make it through a boring afternoon meeting without falling asleep, then you're probably getting the right amount of sleep. It's easy to stay alert during challenging and interesting activities. Well-rested people are able to en-dure monotonous, sedentary tasks without feeling drowsy and do not feel sleepy until bedtime. Once in bed, they may take between 10 and 20 minutes to fall asleep.

Here are some indications that you may not be getting enough sleep:


  • You need an alarm clock to wake you up at the appropriate time.
  • You struggle to get out of bed in the morning.
  • You feel irritable, tired, and stressed during the week.
  • You have trouble concentrating and remembering.
  • You fall asleep in warm rooms during meetings or classroom training.
  • You need a nap to get through the day.
  • You feel drowsy while driving.
  • You fall asleep within five minutes of going to bed.



Sleep loss is cumulative and creates a sleep debt. Larger sleep debts require greater amounts of restorative sleep to return the body and mind to normal, rested levels. In a controlled study, people who slept only four to five hours per night for one week needed two full nights of sleep to recover normal levels of performance and mood. Habitually compromising sleep over a long period of time leads to chronic sleep deprivation.

Sleep deprivation affects mental processes and intellectual abilities. Studies of third-year medical residents show that losing only one night's sleep caused medical knowledge test scores to drop to first-year level. Sleep deprivation impedes decision making and memory. It reduces performance on challenging tasks and negatively affects psychomotor skills. Mood, productivity, and communication skills suffer. Increased rates of errors and on-the-job injuries are also attributed to sleepiness and fatigue. Extended periods without sleep may cause hallucinations and paranoia.

Physical and mental performances are not the only casualties of sleep deprivation. Even a minimal loss of sleep impacts general health. Chronic lack of sleep can contribute to serious health problems and even shortened lifespan. In a 1983 study at the University of Chicago, rats kept from sleeping became sick and died after two and a half weeks. Sleep-deprived rats that became ill but were then allowed to sleep recuperated fully.

Lack of sleep may slow glucose metabolism by 30 to 40 percent and increase levels of the stress hormone cortisol. Sleep deprivation has also been linked to inadequate levels of the hormone leptin. Leptin signals the body to stop eating when it's full. Decreased levels of leptin lead to increased carbohydrate cravings and eating.

Other effects of chronic sleep deprivation include depression and mood swings; gastrointestinal dysfunction; adult-onset diabetes; menstrual and infertility problems; increased use of drugs and alcohol; impaired sexual function; less satisfaction in personal and domestic pursuits; increased appetite and weight gain; and personality changes, particularly loss of humor and increased ill temper.

Chronic sleep deprivation may be difficult to recognize. Says Dr. James B. Maas in his book Power Sleep: "Often we are totally unaware of our own reduced capabilities because we become habituated to low levels of alertness. Many of us have been sleepy for such a long time that we don't know what it's like to feel wide awake."

People suffering from sleep deprivation may not recognize their sleepy condition or the fact that they are making mistakes. Micro-sleeps, brief episodes of unintended sleep, last only a few seconds but can result in serious accidents. Sleepiness can also cause automatic behavior syndrome, or "sleeping with one's eyes open." Lasting several minutes or more, a person continues to perform routine duties but is incapable of active cognition. An example would be a train engineer who remains at the controls but does not recognize a warning signal on the track. The victim of this behavior usually has no memory of the incident.


Short-changing the body on sleep can have disastrous consequences. A combination of excessive overtime, insufficient sleep, and irregular working hours contributed to the critical decisions that led to the fatal 8 a.m. launch of the space shuttle Challenger in 1986. When the Exxon Valdez ran aground in 1989, the crew member at the helm was "severely sleep-deprived and apparently asleep on his feet." A 1984 head-on collision of two Burlington-Northern freight trains was blamed on a train engineer and crew's falling asleep; five crew members were killed and seven locomotives destroyed.

No one is immune to the effects of sleep deprivation, including emergency services workers.


  • A police officer notices an ambulance stopped in the middle of an intersection with emergency lights and siren activated. He discovers both crew members asleep in the cab.
  • On arrival at the hospital with a critical patient, the paramedic driving an ambulance finds the patient still unconscious and his partner asleep in the jump seat.
  • The driver of a fire engine arrives at an early-morning emergency scene and doesn't know where he is or remember how he got there.
  • A rescue worker is killed when he falls asleep at the wheel of his car and hits a tree after a lengthy search for a missing child. He had not slept in 23 hours.
  • While transporting a noncritical patient early in the morning and four hours into overtime, an ambulance driver stops for pedestrians. Mistaking the stop for arrival at the hospital, the attendant opens the side door as the driver starts forward again, damaging nine parked cars.



Firefighters must operate around the clock out of necessity. Researchers have studied the impact of sleep deprivation on pilots, military personnel, truck drivers, and shift workers in various occupations, but few have focused on firefighting and EMS. Stress and the unpredictability of emergency work set firefighters apart from other occupations studied by researchers. Even so, the effects of sleep deprivation and night work are shared by all shift workers and translate easily into the fire service.

The human body was not designed to work around the clock. Firefighters who work 24-hour shifts, a common fire service schedule, are subjected to lack of adequate sleep and interrupted sleep on duty because of alarm responses. They may not be able to obtain adequate sleep off duty because of family demands, daytime noise, and fighting their biological clocks.

Shift work in general interferes with circadian sleep patterns and creates sleep deprivation. This in turn leads to fatigue and accidents, both on and off the job. According to Dr. Maas, shift workers are 40 times more likely than day workers to have accidents at work, on the road, and at home. Sleep expert David Dinges, Ph.D., estimates that human error causes between 60 percent and 90 percent of all workplace accidents. "Inadequate sleep is a major factor in human error, at least as important as drugs, alcohol, and equipment failure," he says.

Circadian rhythms affect alertness as much as lack of sleep. Workers are at greater risk for making critical errors during late-evening and early-morning hours. The nuclear accidents at Three-Mile Island and Chernobyl; the Exxon Valdez oil spill; and the catastrophic chemical leak in Bhopal, India, all occurred during early-morning hours. Studies show that most injuries in shift workers occur between 10 p.m. and 2 a.m. The National Highway and Transportation Safety Administration found that truck drivers are 16 times more likely to have accidents in the early-morning hours.

Tasks requiring brief, intense concentration can be performed with little impairment after sleep loss, but alertness and persistence are lost, and monotonous tasks suffer. Research suggests that emergency responders can temporarily overcome fatigue on critical calls but not so much on routine calls. Nothing can compensate for sheer exhaustion.

Shift workers are more prone than day workers to heart attacks, ulcers, depression, and serious sleep disorders. They are three to four times more likely to have sleep apnea than the rest of the population. Studies with animals suggest that rotating shifts contribute to diminished longevity. Night work is considered a compensable cause of premature death in Japan.

Adaptation to shift work appears to be a combination of biological, sleep, and social factors that vary by individual. Generally speaking, those who biologically require less sleep fare better in shift work than those who need more. Extreme morning people suffer more from shift work than "night owls." Age is also a factor. After age 25, the ability to withstand night shifts decreases. Workers in their late 40s or early 50s become even less tolerant to the demands of shift work. Gender differences in coping are more likely attributable to societal and domestic demands than biological differences, since many women are also the primary caretakers of children and households.

During a 1983 congressional hearing on shift workers, sleep researcher Dr. Charles A. Czeisler stated, "... it has been assumed if an individual is 'tough,' he or she should be able to handle almost any type of schedule. We must now begin to awaken to the fact that this simply is not so." Each person adjusts to shift schedules differently. For some people, their physiology doesn't allow them to adjust at all. Others, however, experience peak performance at night. They are the exceptions among those who work nights or rotating shifts.


In the United States, firefighters work a variety of shift schedules to cover 24-hour operations. Work periods range from eight to 24 hours. Regardless of the schedule, alertness and performance suffer when personnel work during the hours when the body wants to sleep.

In 1994, University of Connecticut researchers Michael J. Paley and Donald I. Tepas published a study of firefighters working an eight-hour rotating shift schedule. In this schedule, firefighters worked the day, afternoon/evening, or night shift for five consecutive days with two or three days off. Over the course of the two-week shifts, the study showed that night-shift workers slept less than day and afternoon/evening shift workers. These findings were similar to a sample of industrial workers on the same schedule. Firefighters on this schedule suffered decreased mood and greater sleepiness on the night shift and were unable to adapt to the changes in their sleep schedule.

Research indicates that the "direction" of rotation has a significant impact on worker fatigue and productivity. Schedules that move workers from days to nights to evenings, for example, do not allow for adequate adaptation. The recommended rotation is from day shift to afternoon/evening to night shift.

Paley, Tepas, and Jana M. Price published another study in 1998 in which they replaced an eight-hour rotating schedule with two 10-hour day shifts followed by two 14-hour night shifts and four days off. This schedule provided for a faster rotation from day to night shifts and limited exposure to night-shift work. Results suggested that the faster rotation improved health and well-being and reduced sleep difficulties and feelings of fatigue on the job. Time off following the second day shift and last night shift also seemed to offset chronic sleep debt effects. Firefighters reported significantly greater satisfaction with the new schedule. However, longer hours promoted increased sleepiness and decreased mood as the shift progressed. The night shift also experienced more sleep loss than the day shift, despite the opportunity for sleep at the station.

There is still little research about 24-hour shifts. In a 1999 letter to the author, William G. Sirois, senior vice president of Circadian Technologies, Incorporated, commented, "This is particularly frustrating to us because we have the technology to scientifically establish their (24-hour shift) impact on employee health, safety, and performance." Circadian Technologies is a consulting and research firm specializing in shift-work scheduling and training.

Several EMS systems changed their traditional 24-hour schedules, citing rising call volume resulting in chronic fatigue among emergency crews. Overworked EMS personnel experienced a deterioration of mental and physical health; as the call volume increased, so did sick time usage. Explaining why his department considered changing work schedules in 1993, former Austin, Texas, Director of EMS David Wuertz said, "Twenty-four hour shifts stop making sense when workers average 18 calls in 24 hours and stay awake most of the night .... The public has an absolute right to people who are alert." Twenty-four hour shifts also disrupt family and social activities and contribute to emotional exhaustion and burnout.

The success of the 24-hour schedule depends on how much workers are awake during the night. Marty Klein, Ph.D., author of The Shiftworkers Handbook, does not support 24-hour shifts for EMS workers unless they work in systems with low call volumes. Instead, he advocates 12-hour shifts to minimize circadian rhythm problems, avoid commuter hassles, and facilitate family/social interaction.

There is no perfect shift schedule. Different operations require different work systems, and there are advantages and drawbacks to each type of schedule. Assistance is available from companies and consultants who specialize in evaluating operations and work schedules. Deciding which schedule works best for any given system is a complex process of pitting call volume against stress and efficiency against employee preference. In their 1998 report, Paley, Price, and Tepas observed, "No magic bullets exist ... even when schedules are seemingly improved, problems associated with shift work in general and night work in specific will remain."


Quality sleep is the primary weapon in the battle against sleep deprivation. Firefighters must take advantage of opportunities for sleep, both on and off duty. Sleeping areas at home and at the fire station should be quiet and dark, and the room temperature should be cool. A comfortable, good-quality mattress is a must. Invest in comfortable bedding and pillows as well. Good sleep habits are essential. Firefighters need to get an adequate amount of uninterrupted sleep every off-duty night. Going to sleep and waking up at the same times every day, even on weekends, is important for maintaining the body's natural rhythms.

Other tips for quality sleep include the following:


  • Avoid eating, reading, and watching TV in bed.
  • Avoid nicotine prior to bedtime. Better yet, give up tobacco altogether.
  • Restrict caffeine intake, and avoid caffeinated drinks at least six hours before bedtime.
  • Eat healthful foods. Do not eat large meals within four to five hours of sleeping.
  • Do not use alcohol to induce sleep. The effects of alcohol-induced drowsiness last only a few hours and cause poor-quality sleep.
  • Avoid long-term use of over-the-counter sleeping pills. Habitual use can reduce effectiveness and lead to addiction.
  • Reduce life stress as much as possible.
  • Use relaxation techniques to relieve stress and invite sleep.
  • Exercise, but not more than four hours before bedtime. For 24-hour shift workers, outdoor exercise during daylight hours can help the body maintain natural biological rhythms and increase sleep quality off-duty.


Daytime sleep after a night shift is essential to staying well rested, but trying to sleep when the rest of the world is awake can be challenging at best. The shift worker must emphasize to friends and family the importance of restorative sleep and enlist their support and cooperation. Daytime sleep should be scheduled on the family calendar along with ballgames, school meetings, and other activities. Telephones should be removed from the sleeping area and silenced. Sleeping areas may need additional soundproofing and darkening to block daytime noise and sunlight.

Napping is an effective coping strategy that can be used in anticipation of a long night or during extended operations. Naps as short as 20 minutes can be effective. Two-hour naps during around-the-clock operations are highly restorative.

Melatonin may help promote better sleep, particularly during the day. However, this supplement is not FDA-approved, and current research is contradictory on short-term and long-term effects.

People who are regularly unable to sleep should consult their physicians to rule out underlying health problems. Doctors may also be able to prescribe medication to help with sleep. Sleep disorders can be aggravated by shift work. Shift workers with diagnosed sleep disorders need to work closely with their physicians to effectively manage their disorder.


Firefighters and other shift workers have a responsibility to report for duty rested and ready for work. Just as an employee should not report for duty if intoxicated, fatigued workers should stay home rather than endanger themselves and their coworkers. During the course of a shift, firefighters need to monitor their own levels of fatigue and watch out for their coworkers as well.

Fire departments have a responsibility to teach their employees how to manage shift work and sleep deprivation. Education should begin with the first day of orientation and be presented as part of ongoing health awareness and safety programs. Periodic physicals are recommended to identify health problems associated with shift work. Supervisors should be trained to identify fatigue in workers and must carefully monitor employees for fatigue symptoms. For liability reasons, if an employee complains of being overly tired, management should consider sending him home.

Other suggestions to consider for managing employee fatigue include the following:


  • Evaluate crew sleeping quarters for darkness, quiet, temperature control, and overall comfort. Make upgrades as necessary to provide the best sleep environment possible.
  • Allow tired employees an extra hour or two of sleep, even after shift change, to help keep them awake on the drive home.
  • Limit the number of consecutive hours an employee may work, including regular hours, overtime, and time trades. Enforce the policy.
  • Modify work schedules to better accommodate increasing alarm loads.
  • Provide additional staffing and response units during periods of peak-alarm activity.
  • Rotate busy units/crews with slower units.
  • Limit the length of time personnel can be assigned to busy companies. Lengthy assignments to the busiest companies can lead to burnout; poor attitudes; and, potentially, health problems stemming from chronic lack of sleep.


Fire departments need to address fatigue, sleep deprivation, and the effects of shift work in accident and injury investigations. These factors may easily be overlooked, and the accidents may be falsely attributed to other causes. Even when addressed, the involved parties may deny fatigue because of personal pride and a desire not to look "weak." Accident reviews should include, but not be limited to, the following:


  • hours of consecutive duty at the time of the accident,
  • the time of day relative to the biological clock,
  • hours since last consolidated sleep,
  • duration of last consolidated sleep,
  • cumulative sleep deprivation over past week,
  • timing and duration of naps since last consolidated sleep, and
  • ingested chemical stimulants/depressants.


Ignoring shift-fatigue problems can expose employers to litigation and lead to reactionary legislation. An Oregon court has already established that employers are responsible for monitoring employee fatigue and that an employer may be held liable for injuries sustained by fatigued and sleepy employees. Individuals may also be held liable in drowsy-driving crashes. Tired New Jersey drivers involved in fatal crashes could face up to 10 years in prison and fines up to $150,000.

Twenty-four hour work schedules have been called a "sacred cow" of the fire service. Many employees find these schedules desirable, and few are willing to sacrifice the benefits they provide. But the time has come to reconsider the 24-hour workday. Ever-increasing alarm loads place demands on a human body that was not designed to operate around the clock. The impact to health and performance can no longer be ignored. Fire departments need to evaluate their operations and the impact of their shift schedule on employees. Whether or not alternate schedules are implemented, workers must be educated on the effects of sleep deprivation and shift work. Employers and employees alike are responsible for identifying and managing the effects of sleep deprivation. Finding solutions will help firefighters and those they serve.