Header: Safety Zone Newsletter with Forest Service Fire Operations Safety Council logo. Background is a fire burning in the distance.

Issue 4
January 2005

“Give Us This Day, Our Daily Rest”

Physical conditioning, regimented diet, and safety refreshers are all essential ingredients for personal preparation for next fire season and most likely your next fire assignment. While you can probably add additional items to the above, consider this “sleeping giant” of concern:

“The impact of disrupted sleep cycles and circadian rhythms is a key factor when personal decision-making ability is necessary during critical situations.” It is very important to understand how the mechanics of alertness, sleep cycles, and circadian rhythms interact to affect personal, “decision-making readiness.” With regards to “normal” cycles of sleep and wakefulness, once you get outside your normal average of sleep, decision-making becomes not only a personal safety issue, but a primary concern for those who depend on the decisions you make for the group!”

Many sleep science experts agree that most adults need 8 hours of sleep every night. Research indicates that individual needs are genetically determined, and vary – but only slightly. Cumulative sleep deprivation or “sleep debt” grows over time. While most people can recover from sleep debt with two good nights of sleep, you cannot “bank” sleep. When sleep deprived, you are classically okay with well-learned behaviors, for example: staying between the lines while driving. However, if required to react to new stimuli, such as an unexpected pedestrian crossing the road, reaction time failures frequently occur. (www.nwcg.gov/teams/shwt/WR-LOAStandards2004.pdf).

The amount of sleep and the nature of your sleep patterns change as you age, with sleep becoming less deep and more disrupted. While total nocturnal sleep decreases as you age, it is significant to note the need for sleep does not. Classic patterns of circadian rhythms and associated sleepiness occur at 0300 to 0500 and 1500 to 1700 each day in association with the time zone to which you are acclimated. Also, your body temperature will drop as your body clock anticipates this slow down. If you find yourself driving (www.nwcg.gov/teams/shwt/DrivingStandards2004.pdf) while fatigued at these times, your body may push you toward “micro-sleeps”.

In transportation accident investigations where fatigue impacts have been implicated as causal, most stem from an interaction between sleep loss and disruption of circadian rhythms. In aircraft crew settings where operational safety awareness is tied to shared monitoring of systems and identifying potential hazards, the impacts of collective fatigue on all crew members tends to shut down communication within the crew, too often with deadly results.

How did this come to be a problem? Modern society has come to accept the need to respond to the 24/7 requirements of life. We think we can easily adapt to shift changes and cross country travel. We feel that “cat naps” on the plane or in the waiting room can catch us up on sleep deficits. Or that vigorous exercise prior to bedtime can help us get to sleep even though our “personal” clocks tell us it’s too early to lie down. There are merits and limits to both of these prospects, as part of an understanding of how our body is physiologically programmed for daily recovery with productive sleep. Personal preparation for fitful performance on the fire line, as well as safe travel to the fire and back can be aided with an understanding of sleep effects.

Before you can tell the world “you’re good to go”, you may need to ask your body if it agrees. Being able to interpret that reply next summer may require some study now.

"Newsletter of the Forest Service Fire Operations Safety Council"

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