Your biological clock tells you when it's lunch time, gives you pep at certain times of day, and affects your body temperature. Most people's clocks run on a daily rhythm of approximately 24 hours. Many teenagers and young people have clocks that make it easy to stay up late and sleep late. As people get older, they tend to wake up earlier and go to bed early. Almost everyone's clock is programmed to make them feel sleepy in the middle of the afternoon and this can be a dangerous time.
Night time is especially risky for drivers.
Most people are programmed to sleep when it's dark, and sleep becomes irresistible late at night. Once you are aware of your personal cycle, you can take extra care when you're likely to feel sleepy. Here are seven statements about sleep. See if you can tell which ones are true and which are false. Coffee overcomes the effects of drowsiness while driving.