We are living in an age when many activities that used to occur only during the day, like shopping and banking, now take place at any time of the day or night. But the technological advances that have made such a 24/7 society possible, have also deprived us of what we really need: a good night's sleep.

Since the Industrial Revolution and the invention of the light bulb, modern society has experienced

Sleep and alertness expert Mark Rosekind

increasingly long hours of continuous wakefulness. According to sleep and alertness expert Mark Rosekind, that affects how well people can think and act. "Two hours less sleep than you need is enough to impair your performance as if you've been drinking 2 to 3 beers and had .05 blood alcohol level," he says. "So not getting enough sleep can impair your performance. At the other end, we know that getting the optimal sleep you need boosts your performance by as much as 30%."

After spearheading the Fatigue Countermeasures Program at the U.S. space agency in the 1990's, Mr. Rosekind turned his attention to athletes. He has been working with the Hilton Hotels Corporation, a sponsor of the U.S Olympic team, to improve the quality of sleep for the U.S athletes. "Specifically, what we did was look at aspects of the physical environment, how to make a bedroom darker, quiet… cooler is better than warmer when you sleep," he says. "One of the things that Hilton did was to bring blackout curtains to the athletes' rooms at the U.S. Olympic training facility in Colorado Springs. Another big area, for all of us actually, and especially athletes, is to look at the bed." He says the athletes now have full size beds instead of singles, giving them more space. In addition, they have more pillows and blankets than previously, so they can adapt their sleep environment to their comfort level.

After completing a makeover of 160 bedrooms at the Olympic training facility, Mr. Rosekind says, they started to get positive feedback from team members. "For example, Apollo Ohno, the speed skater, was the first athlete to have his room made over by Hilton," he says. "And Apollo Ohno has already talked about how important sleep is and how he can see the difference in his performance."

And it is not just athletes who can see a difference. Mark Rosekind says children and teenagers also need to realize how important sleep is for their physical health and performance. "Kids and young people need more sleep than adults," he says. "The average they need is closer to 9 hours." But most kids today get only 6 or 7 hours sleep, he notes, adding, "When they are not getting it, it's going to affect their learning, their development and basically all aspects of the quality of their life."

Jodi Mindell, of the Sleep Center at the Children' Hospital of Philadelphia, is very familiar with what happens to kids without a good night's sleep. "Children who don't get enough sleep are cranky and irritable," she says. "They also have a hard time

Sleep expert Jodi Mindell

regulating their emotions. It affects their behavior. So you're going to see them more over active, more non-compliant, not listening well to their parents. It also affects their cognitive ability, how well they think -- things like attention, memory and decision-making and problem solving, all the things that are absolutely critical for school performance. So how well you do in school is going to depend on how well you slept last night."

Ms. Mindell says school is one reason many teenagers don't get enough sleep. "Our teenagers are getting up so early in the morning to get to school," she says. "Some high schools start at 7:15 or 7:30 in the morning. The second reason is that there is a biological shift, which is the internal physical shift in their body rhythm clock after puberty. So, if you have a 13-, 14-, 15-year-old who used to be able to fall asleep at 9 o'clock at night, they now can't fall asleep until about 11 o'clock. They shift later at the same time they have to get up early to get to their high school. A lot of our teenagers are working. We have very clear data showing that teenagers who work, especially those who work over 20 hours a week, don't get the sleep they need. On top of that they have a huge amount of after-school activities, socializing, homework and they're also into instant messaging at night."

Ms. Mindell says sleep problems among children and teenagers are often overlooked by teachers, coaches, doctors and even parents. However, she says, parents can do a lot to ensure that their child gets enough rest. "First of all, they should have a set bedtime so your child gets the sleep that they need," she says. "The second thing is the bedtime routine. It's just as important for 5 year-olds, 10 year-olds and even 15 year-olds. It's a way to wind down for the day. You want the bedroom to be cool, dark, quiet and comfortable."

Jodi Mindell says parents should pay attention to what she calls the 'sleep stealers' in their children's bedrooms: television sets, video games and computers. She says like eating a balanced diet, wearing seatbelts and using sunscreen, getting enough sleep is a necessary part of a healthy lifestyle. She encourages parents to lead by example and make sure they get a good night's sleep, too.