This is the horrific moment a woman desperately tried to help a man after he overdosed from an opioid behind the wheel.

The unidentified man was nodding off in the driver's seat of a van at Lee Road and Broadway Avenue in Maple Heights, Ohio, when a female bystander approached with their cell phone camera on and realized he was overdosing on a drug.

Jennifer Dillon was driving and the man's van blocked her path. So, she and a friend got out of their vehicle to see what was wrong.

The pair found the man around 10am on March 28 with his van in gear and his foot on the break at a red traffic light. When they approached his vehicle they realized he was gasping for air.

An unidentified man (pictured) was overdosing on a drug in the driver's seat of a van at Lee Road and Broadway Avenue in Maple Heights, Ohio

Jennifer Dillon (hand pictured left) approached the man (pictured) and began to record the incident on her cell phone

In the disturbing cell phone footage, the man's (pictured) mouth is open, his eyes sunken miserably into an ashen face

As her friend called police, Dillon began to record the incident on her cell phone.

In the disturbing cell phone footage, the man's mouth is open, his eyes sunken miserably into an ashen face.

'Hey dude! Hey! Hey! Hey!,' yells Dillon. 'You gotta wake up man! You gotta wake up! You cannot die!'

Dillon can seen shaking the man in an attempt to wake him up.

A police officer shortly arrives and leans into the man's van to check on him.

At one point, the man's eyes roll back into his head (left) and he gasps for air (right)

An ambulance comes later and the man is revived with a dose of Narcan, an antidote that reverses the effects of an opioid overdose, before he is rushed to the hospital off camera, Cleveland 19 reports.

This is the latest example in Ohio of motorists driving while drugged, Lieutenant Don Grossmyer with the Maple Heights Police Department told NBC.

Grossmyer said he does not have data on this troubling trend, but the department began to take notice last year.

Opioids are not normally used while people are driving, said JT Griffin, chief government affairs officer for Mothers Against Drunk Driving.

'The stories you hear are horrible. You hear of parents getting high in cars and just passing out,' Griffin said.