see also:

• sleep
• physiology of sleep
• insomnia
• fatigue
• stress
• Coping with shift work
• managing jet lag and your body clock

• sleep disorders, excessive daytime sleepiness and dangers of driving with its legal ramifications:
  • Australian Roads
  • Australasian Sleep Association
• perhaps your body clock is set early in life and inherited from your mother as with zebra fish
• daylight savings and sleep disruption
• caffeine and guarana helps drivers stay alert and the guarana effect starts at ~1hr and lasts for ~5hrs

• sleep hygiene includes a number of social & behavioural interventions:
  • routines that incorporate the following techniques will help even older people, whatever their residential setting, have a better sleep:
    • establish sleep/wake activity regulation:
      • get up at the same time each day regardless of the amount of sleep that night - avoid over-sleeping
      • going to bed at a constant time is not as important, but might help
      • avoid daytime naps esp. in late afternoon as total sleep hours is preserved so night sleep will be less - restrict to 10-15min afternoon powernaps
      • exercise regularly but at least 6 hours before bedtime
    • create an optimal sleep setting:
      • use bed only for sleep & sex, not for eating, reading or watching television - avoid excessive time in bed
      • bedroom should be comfortable & quiet & not the focus of arguments, anger or distress
      • indulge in relaxing evening activities do not do exercise late in evening
      • avoid alerting and stressful ruminations before bedtime
      • avoid stimulants such as caffeine & nicotine for 2-3hrs before going to bed (some say no caffeine after lunch and no nicotine after dinner)
      • avoid large evening meal
      • reduce excessive alcohol intake
      • avoid pink noise as it is thought to reduce REM sleep and interfere with sleep recovery ¹⁾
      • if unable to sleep, avoid clock watching, get up and do something
    • sleep promoting adjuvants:
      • light snack or warm bath before bed
      • engage in quiet activities before sleep eg. reading
• sleep air temperature
  • ideal sleep air temperature is probably 18-22degC
  • WHO recommends minimum temperatures of housing should be 18degC
    • temperatures below this increase health adverse effects including hypertension, bronchospasm
  • temperatures above 24degC increase physiologic stress especially in those aged over 65 yrs, and especially as temperatures rise above 26degC

• disrupts circadian rhythm
• disrupts sleep cycles and ability to get to sleep
• it is likely that it disrupts the usual menstrual cycles linked to the moon phases
• a 2025 study showed those most exposed to night time light had a 56% higher chance of heart failure and 47% more likely to have a heart attack and that women and younger people were especially vulnerable to the impact of light exposure at night - women exposed to high levels of night light had similar heart failure risks to men, which is unusual because women typically have some natural protection against heart disease ²⁾

• for memory formation, it is not only crucial that slow brain waves occur, but also how they propagate throughout the brain
• randomly played non-targeted acoustic stimuli such as clicking noises disrupt deep sleep with the slow brain waves typical of this sleep phase occur less frequently and spread more irregularly across the brain and this can impair the consolidation of new memories - total sleep time may not be affected as light sleep duration increases at expense of deep sleep. ³⁾
  • perhaps this is why many campers hate caravans with diesel heaters as these heaters produce constant clicking noises