As summer's sweltering heat returns, doctors stress that it's important to stay hydrated.
However, a new study said that the majority of children and teens in the U.S. are not drinking enough water, and that could lead to problems later in life.
Ori Sine, 16, admitted that he does not drink enough.
“I know I should drink more but I just don't,” he said.
He's not alone.
The study from Harvard University found more than half of U.S. children and teens are not adequately hydrated, likely because they aren't drinking enough water.
Doctors said even mild dehydration can cause headaches, irritability, poorer physical performance and reduce the ability to think.
“For kids, we're worried about the impact on the brain and their ability to learn if they're not well hydrated,” said Dr. Deborah Lonzer, a pediatrician at the Cleveland Clinic Children's Hospital.
Nearly a quarter of the 4,000 children and teenagers in the study said they didn't drink any plain water at all.
Lonzer said water is a better way to hydrate than soda, juice and even sports drinks.
“If you're drinking a sport drinks, it's putting more salt in you as well so it helps with hydration but it also adds to the salt load you have to get rid of,” she explained.
Experts said if someone feels thirsty or their lips tingle, they're probably dehydrated.
They said many children, including Shine, don't realize it.
“I just get lost in the game and I don't really feel like I need it,” Shine said.
However, he said he'll try to remember to drink more water.
As for how much people should drink each day, doctors said it depends on a few factors. However, the average is about 96 ounces.
Copyright 2015 WFSB (Meredith Corporation). All rights reserved. CBS contributed to this report.