Many studies make it clear that sleep deprivation is dangerous.

• Sleep-deprived people who are tested by using a driving simulator or by performing a hand-eye coordination task perform as badly as or worse than those who are intoxicated.
• Sleep deprivation also magnifies alcohol's effects on the body, so a fatigued person who drinks will become much more impaired than someone who is well-rested.
• Since drowsiness is the brain's last step before falling asleep, driving while drowsy can - and often does - lead to disaster. Caffeine and other stimulants cannot overcome the effects of severe sleep deprivation.