FDNY firefighters and emergency medical technicians will begin carrying Naloxone on Tuesday -- a medication that rescues patients who have overdosed on heroin or prescription opiods.

EMTs and firefighters began training in March to administer the nasal spray that reverses the effects of narcotic overdose. Now, all 205 engine companies and basic life support ambulances, which are often the first on the scene in a medical emergency, will carry the drug. That increases the likelihood that patients will receive the medicine -- popularly known by its brand name, "Narcan" -- in time to save their lives.

The firefighters and EMTs join 905 paramedics -- who have been carrying naloxone for more than 40 years -- who have already used the life-saving medication 3,200 times this year.

Heroin-related overdose deaths in NYC related to heroin increased by 84% between 2010 and 2012, after four years of decline, while overdose deaths related to prescription painkillers increased 233% between 2000 and 2012, according to the New York City Department of Health and Mental Hygiene.