Working between the hours of 0000 and 0600: A work situation in which the individual is working between the hours of 0000 and 0600 is likely to cause a greater propensity for sleep than one where persons are working during daylight hours. FMPs designed to address the issues of working the night shift or the midnight shift should address education issues as a significant preventative measure. Additional components of the FMP should include adequate time for sleep, use of nonprescriptive stimulating foods or beverages, activity, and alertness enhancing environments. (5-3A) Eight-hour midnight shifts: Persons working during 0000 and 0600 are faced with considerable obstacles to overcoming fatigue and maintaining alertness. This is largely due to the fact that they are combating the body's natural circadian rhythm that is telling the body to sleep. Figure 4 shows the estimated effectiveness levels predicted by the fatigue model that can occur indicating that the person spends about 50% of the time below the optimal effectiveness or alertness level. Studies have shown that alertness and the ability to pay attention is at its lowest point during this time period. There is also a much greater likelihood of traffic accidents during this time as well. This work period is made more difficult by the fact that since the person is not sleeping during the night, they must make up the sleep during the day. Sleep obtained during the daylight hours is less recuperative than that obtained during the night, again due to the influence of the circadian rhythm. Most night-shift workers report obtaining only four to six hours of sleep in the daytime. (5-3B) Education: An educational program, as described above, should include a number of topics related to the nature of shift work, including various types of shifts, biological rhythms sleep and fatigue, effects of fatigue on performance, sleep hygiene techniques, and general health and wellness issues. The effects of the education program should ultimately be to prepare an individual to use their knowledge to obtain adequate sleep and rest prior to, and after, working during 0000 to 0600 periods. A secondary aim of educational programs will be to ensure that employees have adequate knowledge to combat fatigue when they are at work. A number of preventative measures should be described in the education program. For example, getting as much sleep as possible before going on duty, and avoiding extended work hours before pulling a midnight shift. Trying to sleep in the morning immediately after work is a good strategy as well. (5-3C) Time for Sleep: Ideally the person working the midnight shift should have had sufficient time for sleep before going on duty. The importance of the person being well rested before going on duty is underscored by the fact that alertness and performance are directly related to amount of time awake. One of the highest risk scenarios is for a person to be awake during the daylight hours and then be expected to work during the 000-0600 period. While a well-rested person can likely accomplish this, other factors such as boredom, darkness, and lack of stimulation can increase the drowsiness and sleepiness experienced during this time period. Furthermore, a person who has been awake for a number of hours and is then expected to remain alert during 0000-0600 will be fighting fatigue more than most. Consequently education must alert the employee to the risks associated with this time period. Following a tour of duty in which the individual has been on-duty during the midnight hours (0000 to 0600) there should also be sufficient time off to obtain at least eight hours of sleep. Again, since it is difficult to obtain quality sleep during the daylight hours this recommendation and countermeasure assumes that while difficult it is something that should be attempted. This further implies that there is an assumption that working the midnight shift over time may contribute to the development of a sleep debt. An individual may need additional time off to completely eliminate or pay back the sleep debt. While this is not always possible for persons working night shifts, there should be an acknowledgement of the importance of this principle in your FMP. (5-3D) Naps: For persons working this shift, it is also important to acknowledge the need for time to nap during the midnight hours. Use of break time for short naps should be an acceptable part of the work situation. However, the risks of sleep inertia are more pronounced during this time period and may need to be planned for and anticipated for naps taken between 0000 - 0600. FMPs should address the need for, and the guidelines surrounding, napping for employees required to work between 0000 and 0600. To see the estimated effect of a planned nap during a midnight shift refer to Figure 5 and compare to Figure 4. As can be seen, the planned naps on the second and third work shifts (represented by the inverted triangles) have a delaying effect on how soon the person reaches the cut-off level, and almost prevents the subject from falling below the accepted range of alertness. (5-3E) Effects of planned naps: Naps during this time period are particularly problematic as the body's propensity for prolonged sleep is great and therefore the individual may have difficulty ending the nap or waking up. Therefore, naps should only be initiated if there are sufficient safeguards in place for the individual to awaken. Nevertheless, based on the estimates provided by the fatigue model, the benefits would seem to outweigh the risks. (5-3F) Diet: The judicious use of over-the-counter food stimulants is also recommended. For example, caffeine is useful in improving alertness. Caffeine is found in any number of common foods and beverages, and employees in high-risk situations should be encouraged to utilize caffeinated foods and chewing gum. Of course, to maximize the positive effects of these foods it is necessary to utilize them in an effective manner and to consume them so as to achieve the greatest possible benefit. Again, education should be provided to enable persons to use these products wisely. On the midnight shift, the use of caffeine before the end of shift or after 3 a.m. should be discouraged as it can lead to difficulty sleeping after work. Other dietary issues that occur during the 0000-0600 period have to do with the fact that the body's digestive system is likely slowed or delayed during this time period. Consequently, efforts should be made to limit the amount of food intake during this period. Light snacks, foods requiring little digestive effort such as liquids are more likely to be digested than high amounts of protein. (5-3G) Activities: Several studies have shown that there is some benefit in trying to remain physically active as a means of warding off sleep. The technique of walking around, talking, or performing various duties that is interesting and stimulating as a means of counteracting the effects of drowsiness. One researcher suggests that midnight shifts should be structured with periodic rest breaks and snacks. In addition to being physically active, it is also important to be psychologically active. Engaging in varied tasks and altering your pace can enhance your alertness as well. In sum, short breaks that increase activity are needed to help offset the immediate propensity for sleep. (5-3H) Environment: Whenever possible, positive environmental conditions such as proper lighting, proper temperature, and some appropriate noise level should be maintained. In order to ward off drowsiness and fatigue the environment should be properly lighted. Bright light is more likely to lead to alertness. To the extent possible, bright light should be a part of the environment during 0000 to 0600 work shifts. If conditions permit, bright light will act as a stimulus to increased alertness. Darkly lit environments promote sleep. In addition, noise in the environment should be constantly changing and not monotonous. A social environment where it is possible to talk to others will also encourage alertness. Listening to talk radio or news shows can also enhance attention