How are your reflexes?
Lack of sleep compromises your reflexes, dulling your ability to think and act clearly.
Recent studies purport that a sleepless night might have the same effect on you as alcohol, according to Dr Itzhak Fried, a professor of neurosurgery at the University of California.
Experiments showed sleep-deprived brains dozed, causing mental lapses and sluggishness, while the rest of the brain was awake and running as usual.
The implications can be huge.