text: Sleep Readiness
  the eyes at night can be harmful. Even dim lights emitted from electronics such as a smart phone, computer,
  or television can have a negative impact. This light confuses and resets the brain’s internal clock, which can
  misinterpret such light exposures as either an early dawn or a late dusk. In either case, such exposures
  incrementally weaken the brain’s circadian rhythm of alertness, negatively impacting both nighttime sleep
  and daytime alertness. Therefore, sleeping areas should be kept dark. Blackout curtains or blinds should cover
  all windows. Leaders need to strictly enforce the lights out policies. To improve Soldiers’ ability to avoid
  unwanted light exposure and thus facilitate sleep, leaders should create separate sleep areas for each shift and
  encourage the use of comfortable sleep masks.
  Safety
  11-70. Operational or training environments should be safe and secure for Soldiers to sleep in. This also
  applies to areas where Soldiers take naps. Ensure that Soldiers do not attempt to nap in front of, behind, or
  underneath trucks, tracked vehicles, or other vehicles. Soldiers need to avoid and protect against pests (for
  example, use mosquito nets when appropriate). Before sleeping, Solders check that snakes, spiders, ants, and
  other creatures are not in the sleeping area, sleeping bag, or shoes.
  SLEEP MANAGEMENT PLANNING TOOL: 2B-ALERT WEB
  11-71. Leaders have a planning decision aid to help plan missions and predict the effects of any sleep-wake
  schedule on performance. This scientifically-developed mission planning decision aid, the 2B-Alert Web, is
  available at http://sleep.bhsai.org. This tool can predict the effects of any sleep-wake schedule on vigilance
  performance, as well as the efficacy of applying both naps and caffeine as fatigue countermeasures at any
  point during a mission.
  RESOURCES
  11-72. Everyone occasionally experiences difficulty sleeping. Such difficulties may be due to anxiety,
  excitement, physical exhaustion or discomfort, travel across multiple time zones, or overuse of caffeine.
  Usually, such sleep difficulties are situational and temporary. They easily resolve with time, a change in the
  situation, or good sleep hygiene practices. For example, a high operational tempo may be stressful and allow
  little time for sleep, or allow for sleep only during the ascending phase of the circadian rhythm of alertness
  (for example, the daytime) when the brain’s clock promotes wakefulness. However, as the operational tempo
  slows and Soldiers reestablish nighttime sleep opportunities, sleep problems will typically resolve.
  11-73. Sometimes, however, sleep problems are more persistent and difficult to address. For example, some
  individuals are able to fall asleep easily at night but then experience early morning awakenings with difficulty
  returning to sleep. Others persistently experience difficulty initiating sleep at night and awakening when they
  need to in the morning. The discussion beginning in paragraph 11-74 provides some self-management
  strategies Soldiers can use to address these relatively persistent sleep problems.
  SLEEP PROBLEMS
  11-74. When Soldiers experience persistent sleep problems despite generally good sleep habits and an
  adequate sleep environment, a more concerted effort to improve sleep is warranted. First, Soldiers must
  evaluate their sleep habits and sleep environment.