A student at Back Bay High School zipped up his sweat shirt,flipped on his hood and carefully tucked his electronic cigarette near the top of the zipper.
While sitting in class, he took quick puffs off the vaporizer without being detected by his teacher.
In the past, it wouldn't have been so easy to sneak a smoke in the classroom, explained Deborah Davis, principal of the Costa Mesa school.
But unlike traditional cigarettes, electronic cigarettes and similar products are virtually odorless and don't emit smoke, making them easier for students to hide.
In the past year, electronic cigarettes have gained popularity, with 10% of high school students in the nation admitting to using them, according to the national Centers for Disease Control.
"It's an emerging challenge here," Davis said. "Their technique is very clever. I think the thrill for kids is getting away with it."
So far this school year, Back Bay administrators have confiscated three electronic cigarettes from students.
When found, administrators seize the device and call the student's parents, Davis said.
In response to the increased use in middle and high schools, the California Department of Education sent out a memo recently encouraging all district boards to amend their tobacco-use policies to include electronic cigarettes and similar devices, including electronic vaporizers, "vapes" and e-hookahs.
The Newport-Mesa Unified School District board, which reviews recommended policies for adoption on a quarterly cycle, has not made any changes to its policy, according to district records.
"It appears that we are covered under the current policy, as state law does not define 'tobacco products' for purposes of the district's tobacco-free schools policy," said district spokeswoman Laura Boss.
However, officials who spoke at a conference sponsored by the Orange County Department of Education on Friday morning, said current district policies may not be specific enough to deter use.
Electronic vaporizers, which come in flavors like bubble gum, vanilla and cherry, sometimes don't contain nicotine, which means they aren't covered under current board policies in many districts, said Stacy Deeble-Reynolds, prevention coordinator for the county education department's Center for Healthy Kids and Schools.
"The flavors may appeal to some adults, but it's definitely appealing to kids," she said.
However, the devices still contain potentially harmful ingredients, such as propylene glycol or glycerol vapor, which is used in theatrical smoke and isn't suitable to inhale, said Helene Calvet, a deputy health officer with the Orange County Health Care Agency.
The long-term health effects are unknown, which is all the more reason to keep them out of the hands of teens, who are more likely to become addicted and continue using them later in life, she said.
"Kids who have never smoked before, and like the flavor and the boost from the nicotine, need to know that these aren't safe," Calvet said. "We're creating a generation of vapers."
Many of the devices also provide teens with a means for using marijuana products, such as "wax," a form of hashish melted with butane, and hash oil, both of which can be smoked in electronic cigarettes virtually undetected, officials said.
It's something Davis said she watches out for at Back Bay.
"We want them to know it's not acceptable," she said. "We're working hard to keep our reputation, and we don't want it on our campus."