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Is the firefighter 48/96 shift a health hazard?

Knowing where firefighters are on this shift and how busy they are can help those running rehab sectors


Chronic sleep deprivation increases risk for hypertension, cancer, ulcers, heart attack and stroke.


“What do you think about the 48/96 shift schedule?” has become one of my least favorite questions when I present on current research findings. It is a difficult question because there is no easy “it is good” or “it is bad” answer based on the science that is available.

What science can tell us is that sleep is important — very important. Your body operates on circadian rhythms, which is a 24-hour cycle of physiological processes.

Going without sleep for too long and interrupting that rhythm leads to physical and cognitive problems. Chronic sleep deprivation increases risk for hypertension, cancer, ulcers, heart attack and stroke.

It also impairs attention, makes you more forgetful, makes it harder to concentrate and impairs problem-solving and reasoning. When at its extremes, impairment from sleep deprivation has been found to be similar to alcohol intoxication.

Science also tells us that sleep deprivation leads to increased risk of accidents, is related to depression and is related to obesity given it interrupts the peptides that regulate appetite.

Science also tells us that shift work is generally bad for your health because it interrupts the body’s natural rhythm for sleep and often leads to chronic sleep disturbance.

A review of literature presented by the International Association of Fire Chiefs outlined several risks and concerns related to shift work — mostly based on the literature available about residents and physicians. In fact, the organizations that oversee regulations about time limits of medical residents has experimented with limiting the hours residents are allowed to work consecutively to improve safety.

Sleep interrupted

While the information is useful, and the short- and long-term considerations seen in health care settings should be considered, it is a challenge to apply the findings of health care settings directly to the fire service.

That’s because of the different requirements and tasks. At a hospital, those treating patients or staffing an ER have to be awake and alert all night.

For most of the fire and EMS community, that is not the case. Rather, they are allowed to sleep between calls and only have to be awake if they are needed.

On one hand, there is a benefit in that personnel can get some rest. On the other hand, as most will readily report, the sleep at the firehouse is usually a lighter sleep. A call could come at any moment, so people are not necessarily getting the deep, restorative sleep that the body requires.

So the question comes back to the 48/96 shift and whether it is a good shift schedule — and the answer (based on the current literature) is “it depends.”

Personnel at departments that switch to the schedule tend to like it. It allows more days of consecutive family time and is more accommodating for second jobs. For departments where the cost of living is high, those who live outside of the immediate area have less commute time.

However, Dr. Laura Barger and colleagues reported in “Current Neurology and Neuroscience Reports,” that injuries for those working 48-hour shifts are highest during the second day of the shift — a finding that is consistent with Executive Fire Officer reports on the topic.

End-of-shift risk

Retired Fire Chief Don Abbott is currently conducting a study on maydays across the country and has found that, for those working 48-hour shifts, the most common time for a mayday to be called is during the final 12 hours of the shift.

A study conducted by Joel Billings and Dr. Will Focht at Oklahoma State University found that, among 109 firefighters surveyed, the Kelly shift schedule led to the worst sleep outcomes.

A significant limitation to the research to date, however, is that shift schedules are lumped together without taking into account the call volume for a specific firefighter or crew.

Unfortunately, emergencies know no time so someone has to be there to respond whether it is 2 in the afternoon or 2 in the morning — but not all stations have the same call volume. Those making policy decisions on shift schedules and risk need to take into account how busy the department is overall.

For a firefighter at a station that is not typically running calls during the night, a 48/96 schedule might not be at all detrimental to her or his health. If, within the same department, there is a station that typically runs several calls during the night, you would expect to see more negative health outcomes.

Dr. Susan Koen, Round-The-Clock-Systems, published a comparative analysis of the 24/48 versus 48/96 work schedules. She reported that, for firefighters who typically have one call during the night (depending on the length of the call and how easy it is for them to return to sleep), they will typically start their second day on shift with only mild sleep deprivation.

For those at busier stations with two or more calls in a night, without an opportunity for rest on the second day, firefighters likely will begin to show cognitive fatigue challenges. She recommends that busy stations that average more than three calls a night should not consider the 48/96 shift schedule.

Regardless of the type of shift schedule work, firefighters have been found to be at high risk for sleep disorders — often disorders that are undiagnosed.

Paying attention to sleep, education about proper screening and treatment for sleep disorders, appropriate use of caffeine and appropriate use of napping for busy stations will likely be useful in decreasing the negative effects of shift work among firefighters.

This article, originally published in 2017, has been updated.

Sara Jahnke, PhD, is the director and a senior scientist with the Center for Fire, Rescue & EMS Health Research at the National Development & Research Institutes - USA. With over a decade of research experience on firefighter health, Dr. Jahnke has been the principal investigator on 10 national studies as well as dozens of studies as a co-investigator. Her work has focused on a range of health concerns, including the health of female firefighters, behavioral health, risk of injury, cancer, cardiovascular risk factors, and substance use, with funding from the Assistance to Firefighters Grant R&D Program, the National Institutes of Health and other foundations. Jahnke has more than 100 publications in the peer-reviewed medical literature. Awards include the 2019 Endowed Lecture at the annual conference of the American College of Epidemiology; the 2018 President’s Award for Excellence in Fire Service Research as well as the Excellence in Research, Safety, Health & Survival Award, both from the International Association of Fire Chiefs (IAFC); and the 2016 John Granito Award for Excellence in Firefighter Research from the International Journal of Fire Service Leadership and Management. Connect with Jahnke on LinkedIn, Twitter or via email.