The 24-Hour Shift: Impact on Health and Safety

The history of shift work in America can be traced back to the beginnings of the industrial revolution in the 18th and 19th centuries. Factory owners realized that they could maximize production by keeping machinery running 24 hours a day. It was this relentless drive nearly 200 years ago that made the United States an economic superpower.

The origins of shift work in the fire service (and eventually EMS) were born out of necessity, as opposed to monetary gain. In cities with populations large enough to have paid crews, it made sense from a public safety standpoint to have people occupying the station at all times. Although some departments rotated crews on an eight- or 12-hour basis, many others chose to work 24-hour shifts, especially when call volumes allowed for adequate rest. Some large-city departments are so busy that they’ve never used a 24-hour shift rotation or haven’t done so for many years. A significant number, however, continue to use 24-hour shifts for fire and emergency medical services.


The benefits of a 24-hour shift are hard to deny. Employees find that 24-hour shift schedules afford considerably more time off than the traditional 9-to-5 shifts. It’s not unusual for 24-hour workers to have the “luxury” of working 120 shifts (or fewer) over the course of an entire year. Ask any shift worker how nice it is to ski, Christmas shop, or hike during the middle of the week. Although 24-hour shift work is attractive, there are downsides. Studies show 24-hour shift work leads to significant wear and tear on workers’ bodies and minds. Some 60 percent of health-care workers report moderate to severe levels of fatigue, the second highest rate of all industries.1 Shift workers’ job performance and family life can be heavily impacted by such stress. In the face of legal, health, and family challenges caused by 24-hour shift work, there is good reason to question whether the risks might outweigh the benefits.


The majority of EMS employees in the United States today work 24-hour shifts. In a recent nationwide survey of paramedics, more than 55 percent of respondents reported working 24-hour shifts; 44 percent reported working eight- or 12-hour shifts. This shouldn’t be surprising: 24-hour shifts are easy and efficient for management to schedule and the time-off benefits greatly appeal to most EMS personnel. Interestingly, run volumes reported by the survey respondents varied as much as the types of shifts worked. Some 24-hour-shift paramedics reported run volumes as high as 240,000 annually, whereas some eight- and 12-hour-shift paramedics reported service run volumes as low as 1,000 per year.


Most people who’ve worked in EMS and the fire service for more than a few years are familiar with the profession’s grim line-of-duty death statistics. More than 20 percent of fire department fatalities each year are caused by vehicle crashes responding to and returning from calls. Although the United States Fire Administration doesn’t break down driving fatalities by specific cause, some of these accidents have resulted from fatigue, and others could have resulted from slow reaction times caused by fatigue. The National Highway Traffic Safety Administration reports that more than 100,000 automobile accidents a year are caused by fatigued drivers.2

The physiological and psychological impact of shift work and the subsequent fatigue it can cause are well studied and documented. Some of the more common side effects of shift work are3

  • increased likelihood of obesity,
  • high risk of cardiovascular disease,
  • high risk of mood swings,
  • gastrointestinal problems,
  • higher risk of motor vehicle crashes,
  • increased likelihood of family problems/divorce,
  • in persons with diabetes, trouble controlling blood sugar levels,4
  • increased risk of substance abuse, and
  • chronic fatigue. (3)

Keep in mind, these are simply the side effects of shift work, and they assume that the person is still getting some regular sleep time. Sleep deprivation, which is more along the lines of what many 24-hour-shift workers face, carries a whole host of additional side effects:

  • increased reaction time (sometimes tripled),
  • lapse of attention,
  • poor motor function,
  • memory loss,
  • depressed immune system,
  • hallucinations, and
  • psychosis.5

You might be thinking that sleep deprivation studies involved people kept awake for days on end. Actually, such “traditional” sleep deprivation studies are relatively rare. Researchers have found it too dangerous to keep people awake for more than 24 hours. Some of the above symptoms have been seen in subjects restricted to only four hours of sleep per night for several nights in a row. It’s interesting to note that a person awake for 24 hours has the same reaction time and critical thinking ability as a well-rested individual with a blood alcohol level of 0.10 percent, a level considered legally drunk in all U.S. states. (5) To put this number into perspective, one study showed that people who purposely consumed alcohol to raise their blood alcohol level to only half the legal driving limit were twice as likely to fail visual acuity tests.6 Australian and New Zealand researchers concluded that going just 17 to 19 hours without sleep caused subjects to exhibit the same cognitive dysfunction as someone with a blood alcohol level of 0.05 percent, a level considered legally drunk in most western European countries. (2) Consider the ramifications of an EMS provider with a blood alcohol content of 0.10 percent caring for a critically ill patient or driving that patient to the hospital.

Health-related impacts of shift work can lead to financial strains on EMS and fire agencies. Researchers have found “extended hour” employees have sick leave usage and turnover rates nearly three times greater than the general population. These same studies have correlated workers’ compensation costs directly to the degree of employee fatigue. (1) The health and financial impacts of fatigued workers may be just the tip of the iceberg. Legal consequences of sleep-deprived workers can have a more substantial impact.


Scenario: You’re close to finishing a 48-hour marathon double shift. You worked your own shift and then agreed to fill in for a sick colleague the following day. After 30 calls in the past two days, you’ve managed to get in just a two-hour “cat nap.” While responding on a call just an hour before you’re set to go home, you nod off briefly and strike another vehicle. The person in the vehicle you hit is critically injured and the patient you were responding to dies, possibly because of the delayed EMS response.

Who’s going to be held responsible for this? A key doctrine of law called respondeat superior holds that an employer is almost always responsible for the actions of employees when carried out while employees are on the “clock” and performing their normal duties. Don’t believe for a moment, however, that this means the paramedic in this scenario is going to get a free pass. If sued by one or both victims in this case, a judge or jury could find that although the employer was 80 percent responsible, the paramedic is 20 percent responsible for damages.7 A million-dollar award could amount to a significant chunk of change paid by the medic. How might this happen? The plaintiff’s attorney could make the case that no one forced the medic to take the second shift when he knew he hadn’t slept the night before and realized he was likely to be fatigued. The attorney might also convince a jury that the medic should have known that working a 48-hour shift was unsafe and, at minimum, he should have spoken up to let his employer know he was too tired to drive. Some states, such as New Jersey, have proposed legislation that would bring charges of vehicular homicide against any driver who causes a death while knowingly driving while fatigued.8

The profession with perhaps the most case law on driving while fatigued is the long-haul trucking industry. In most cases where a fatigued long-haul truck driver has caused an accident, the employer has been held 100 percent responsible both legally and financially. In Florida vs. Rosario, however, a fatigued truck driver was sentenced to 15 years in prison for causing a crash that killed three people. The judge admonished at the sentencing, “You decided to get behind the wheel. It’s like taking a shotgun and shooting into the crowd. That was a chance you took, and you lost big.”

Even though juries may be sympathetic to a fatigued paramedic or a firefighter who causes a crash or makes a medical error (and thus may be more likely to punish the employer for creating the negligent situation), Maryland attorney Mike Jacobs warns that counting on such sympathy is dangerous. “Fatigue is not an excuse,” says Jacobs. “If it were, then everyone in the world who got sued for negligence would just claim that he was too tired to be thinking straight, and it wasn’t his fault.”9 Indeed, fatigue often becomes an issue in medical malpractice cases. “In almost every case where I defend the deposition of a paramedic, nurse, or physician, [fatigue] is an issue that is raised,” notes paramedic and attorney Winnie Maggiore. Every paramedic and firefighter should know what legal protections are in place in their home state. Although state laws vary and personal liability may be limited by statute, relying on this sort of protection is as dangerous as hoping for a sympathetic jury.


Sleep studies are vast and well funded in the United States. Type “sleep deprivation” into Google, and you’ll be inundated with more than nine million studies, surveys, and opinions. Although some research concludes that we can get by with six to seven hours of sleep per night, others find it unhealthy to sleep more than nine hours. The consensus of sleep experts is that the average adult needs seven to eight hours of sleep per night for optimal performance the following day. It is difficult to pin down the absolute minimum amount of sleep needed to prevent impairment of cognitive and motor functions; it likely varies among individuals. Some studies show cognitive breakdown with less than four hours of sleep in a 24-hour period. Severe cognitive breakdown is commonly observed following more than 24 hours of sleeplessness. (5) 10


Relying on run volumes to determine whether a department should be working less than 24-hour shifts can be difficult. Numbers can be misleading in the absence of further department detail. A metropolitan fire/EMS department with an annual run volume of 125,000 calls may seem very busy. If that same department had 25 stations, a rural department running 4,500 calls from a single station may be just as busy as its big-city counterpart.

It’s not an easy task to determine whether your department should consider making a clean break from the 24-hour shift. Such an assessment can be even more demanding if you work in an agency that provides fire and EMS services. Although the medic crew may be in need of a change to 12- or eight-hour shifts, engine or truck crews may not appreciate being forced off their 24-hour shift schedule if it’s not necessary. Although it may be more problematic from a scheduling standpoint, there’s no reason EMS crews can’t be on different schedules than the truck and engine companies. Discovering whether your current shift schedule places the department in potential legal jeopardy requires an objective examination of each crew’s workload. An occasional “all-nighter” shouldn’t be of immediate concern as long as it doesn’t happen more than a few times a year. It would make little sense to switch your crews to eight-hour shifts just because they have one all-nighter when the station has only 2,000 runs per year. If crews experience more than a couple of 24-hour shifts each month with fewer than four hours of sleep, you may want to consider other scheduling options to reduce your legal liability as well as the psychological and physiological impacts on your crews.


There are alternatives to changing shift schedules in the face of daunting run volumes, such as hiring more personnel or scheduling more relief crews, but these options are not always feasible in our current economic climate. In cross-staffed departments, it may be possible to rotate paramedics between engine companies and the medic unit. For instance, medic “A” works the truck company for the first half of the 24-hour shift while medic “B” works the medic unit. Halfway through the shift, they switch. A variety of “sub 24-hour” shift schedules exist in fire and EMS. Keep in mind that some of these shift schedules may require debit days or call time. Some varieties include the following:

  • 5 8-hour shifts/2 days off4 12-hour shifts/3 days off
  • 2 12-hour shifts/3 days off
  • 2 12-hour shifts/2 days off
  • 4 10-hour shifts/4 days off
  • 4 9-hour shifts/4 days off
  • 3 10-hour shifts/2 days off, 3 14-hour shifts/4 days off.

Alternatively, several California departments (and elsewhere) are experimenting with 48/96 shift schedules. That’s right, 48 hours on followed by 96 hours off. By some accounts, personnel seem to like this shift schedule. Hopefully, personnel are rotated in such a way that they get a reasonable amount of sleep every 48-hour shift.


Despite warnings from health and legal experts, it’s likely that 24-hour shifts will be around for the foreseeable future in many departments. National Institute for Occupational Safety and Health (NIOSH) publication 97-145 is an excellent source for coping strategies for extended shift workers. Among the NIOSH recommendations are the following:


Implementing change in a fire department can be a difficult proposition. It requires that we challenge fire service traditions many of us hold dear. Remember how long it took for many departments to use SCBAs? Or how long it took before we realized diesel exhaust filling our stations wasn’t a good idea? Firefighters and paramedics have no special immunity that allows for less sleep than the rest of the population. We need to recognize when it’s time to change work schedules for our benefit and the benefit of the communities we serve.


1. “24-hour shift work practices,” Circadian Technologies, 2004. Retrieved June 1,2006,

2. “Endangering your life and others,’” Sleep Deprivation. Retrieved August 30, 2006,

3. Josling, L., “Shift work and ill-health,” September. Retrieved June 1, 2006,

4.. “Shift work health effects,” Better Health Channel, 2006. Retrieved June 1, 2006, Open Document.

5. Lambert, C., “Deep into sleep,” Harvard Magazine, 2005. Retrieved June 1, 2006,

6. Bowman, L., “Not drunk? Maybe, but did you see the gorilla?” Seattle Post-Intelligencer, July 1, 2006, A7.

7. Kelly, G, “Asleep at the wheel: fatigue and liability in EMS,” Emergency Medical Services Magazine, June 2004. Retrieved June 1, 2006,

8. “ Parents Against Tired Truckers,” Fall 2001. Current news. Retrieved July 1, 2006,

9. Jacobs, W. W., Michael Jacobs, Esq, Columbia, Maryland. Interview with the author. May 11, 2005.

10. Peters, R., E. Kloeppel, E. Alicandri, et al., “Effects of Partial and Total Sleep Deprivation on Driving Performance” (undated). Retrieved June 1, 2006,

Dominick J. Swinhart, EMT-P, is a paramedic/firefighter for the Aberdeen (WA) Fire Department. He’s been involved in EMS since 1989 and is enrolled in George Washington University’s bachelor of science in EMS management program.

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