More people are dying from a heroin overdose in Mecklenburg County than any other county in the state and those numbers are consistent for most of the past decade. Emergency responders and the fire department are adapting to the growing issue of heroin overdose deaths, by carrying a drug that can reverse the effects of an overdose and for some bring them back from the brink of death. In part two of our series, Time Warner Cable News reporter Kate Gaier takes a closer look at the dangerous reality of a deadly high.

CHARLOTTE — Emergency room doctor Christopher Griggs says time is critical when treating a heroin overdose patient.

Dr. Griggs said the period of time between when a patient stops breathing and when they die is pretty short. He said many patients begin with an addiction to other drugs such as prescription pain pills, and heroin is so addicting because of how it impacts the brain.

"In the brain heroin acts on pleasure pathways, same way you get happy when you eat. Heroin works in that pathway almost stronger than other drugs out there. That's why it's more addicting,” said Griggs.

The CDC said the number of deaths increased 172 percent nationwide from 2010 to 2013. In North Carolina, the numbers continue to climb.

NC Counties With Largest Number of Heroin Deaths:
• Mecklenburg
• New Hanover
• Wake
• Guilford

"It used to be the No. 1 killer of anybody in their 20's and 30's was injury related deaths. And that used to be motor vehicle crashes. Just in the past five years it is now opiate overdose and poisoning," said Griggs.

Fire crews and EMS responders across the state have had to adapt to the growing trend, now carrying a drug which in many cases, can reverse an overdose. Narcan or Naloxone can bring a patient back from near death—a quick response making all the difference to reduce the number of cases of heroin overdose.

Some heroin addicts overdose right after a trip to rehab because their tolerance to the drug is lower.