After a summer filled with camp, amusement park trips and swim lessons, switching back to that 6 a.m. morning routine is a rude awakening -- literally.

"A lot of kids get out of a regular schedule in the summertime,” Dr. Dennis Rosen, M.D., associate medical director of the Center for Pediatric Sleep Disorders at Boston Children’s Hospital, tells The Huffington Post, “shifting their internal clocks later, to the point that they’re out of sync with the external clock.”

Those later summertime bedtimes lead to later wake up times for school-aged children, too, he explains, especially teens. But sleeping until noon only causes problems when September rolls around.

“Waking up earlier becomes quite difficult, almost akin to jet lag,” says Rosen. Not only does it feel crummy, he says, but because sleep plays an important roll in processing and consolidating memories, this seasonal version of jet lag can have an effect inside the classroom as well.

Unlike adults, who need around seven to nine hours of sleep a night, children of different ages require a wide range of sleep amounts to be at their best. Preschoolers typically need about 11 to 13 hours of sleep a night, kids up to 12 years old need 10 to 11 hours of sleep a night and teens need about 8.5 to 9.25 hours, according to the National Sleep Foundation.

But the bell rings at most schools in the U.S. at 8 a.m., HuffPost Education reported in May, and 20 percent of kids and teens must report to first period by 7:45 or before, making it difficult to hit the hay early enough to log the recommended winks.

That’s part of the reason a number of sleep advocates have been pushing for later school start times, a move that would not only allow children and teens to get more -- and better -- sleep, but may also aid learning, boost memory and improve grades and overall performance.

So how can you help your children get their sleep on track in time for heading back to school? Many of our favorite sleep rules still apply: Make your child’s bedroom a peaceful environment for sleep only. Take any electronic gadgets out of the bedroom, and keep it cool, dark and quiet. But there are some summer-specific methods the experts suggest, as well.

For more on sleep, click here.

Sarah Klein is associate editor of Healthy Living at the Huffington Post.