Sleep is a biological necessity. All complex organisms have a sleep-wake cycle, from simple fruit flies to humans. In humans, sleep has many vital functions for both physical and mental health. Important experiments where individuals volunteered to be sleep deprived have shown us much about the function of sleep.
We have found that sleep helps to modulate body temperature, conserve energy, maintain the correct weight and maintain a normal immune system. The most important consequence of sleep deprivation is seen on brain function. Individuals with sleep deprivation fail to learn tasks properly as a result of memory disturbance, but also see disturbances of mood and behaviour with hyperactivity, irritability and impairments in attention and concentration.
So, a good night’s sleep is vital for body and brain to work at their best during the day.
The Challenger space shuttle disaster, the Chernobyl nuclear meltdown, and the 1989 Exxon oil spill were all caused to some extent by sleep deprivation.