Fatigue Management

Irritability increased; there was a tendency for people to
fall asleep at O Groups when not being directly addressed.
Lewis Keeble, MC
Company Commander
during the Normandy Campaign
Sleep Disruptions
Many causes of disruption to sleep are obvious: loud noise, pain, bright light,
extremes of temperature and the need to urinate. Others are less obvious and
disrupt sleep without causing awakening; for example, both infection and
extremes of temperature tend to reduce REM sleep. Any disruption to sleep, or
to the sleep cycle, can degrade the recuperative quality of sleep and hence
contribute to fatigue. The inability to fall or stay asleep (insomnia) is one of the
most common sleep disruptions.
I was remorseful, shaken up, wet as a shag, and couldn't
relax. Maybe I caught twenty minutes or an hour's sleep,
then it was daylight.
Private K. Branch
on the morning of 19 Aug 1966
quoted in Lex McAuley's
The Battle of Long Tan, 1986
Insomnia. A common belief is that fighting soldiers rarely complain of
insomnia because they are so exhausted; it is presumed that involuntary
falling asleep is a much more likely problem. This is not the case. Insomnia is
common on operations. Insomnia can be characterised by difficulty falling
asleep, staying asleep and/or waking earlier than intended. Soldiers often
have to snatch sleep when they can so that opportunities for sleep become very
precious and an inability to use them very distressing. Being unable to fall
asleep, even on occasions when the military situation allows it, is a highly
frustrating experience. High arousal in response to the stressors of combat
(typically fear and concern for mates/subordinates) environmental factors,
worry about home and family, and being out of sync with one's normal sleep
cycle, are major contributing factors to sleep-onset insomnia. Difficulties in
staying asleep are also common because of operational noise, sudden
involuntary startle movements and disturbing dreams of battle or other
distressing events.
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