A Westchester County high school student needed to be revived with Narcan after the teen used a vape possibly laced with deadly fentanyl.

The student at New Rochelle High School was smoking a vape believed to be marijuana and went unconscious on Monday. Nurses rushed into action to administer Narcan — a treatment that can reverse the effects of a known or suspected overdose, officials said.

Superintendent Jonathan Raymond called the incident an“ominous milestone” for the district.

“The vape almost cost that student their life. I implore you to speak with your children immediately about the dangers of vaping. It is urgent,” Raymond wrote.

“This device is still in our community, potentially threatening the health or lives of any others who use it.”

It is believed the vape was laced with the deadly opioid fentanyl, according to CBS 2.

“And that’s why we need to get this message out to our families, caregivers and our guardians,” Raymond told the news station. “They need to know and tell their kids that any time you try anything from the street, whether it’s marijuana, off a vape, chances are it’s going to be laced with fentanyl. That’s how bad, that’s how serious, this is.”

He wrote in the community note the district has not confirmed the substance that almost killed the student, but “we know that any vaping devices or drugs purchased on the street may — and likely do — contain the synthetic opioid fentanyl, and even the smallest dose can be lethal.”

CBS 2 reported all school nurses in the New Rochelle school system — which is about 30 minutes from Manhattan — have a supply of Narcan.

Raymond encouraged parents to get their own Narcan prescription and ask their kids to share information about “cartridges, vapes, or other banned items in or around our schools.”

“If at any time they are with a friend who has overdosed, they can call 911 without fear of repercussion,” Raymond wrote. “There is nothing more important than the health, safety, and wellbeing of our students and it takes all of us to prevent a fatal overdose.”