The Leeds, Grenville and Lanark District Health Unit says it's seen a huge spike in fentanyl overdoses this year. Officials believe batches laced with carfentanil are circulating.

Firefighters, EMS and police officers were called to more than 40 drug overdose calls last week. On Friday alone, emergency crews were called to 16 overdoses.

Fueled by a thriving trade out of China, the weapons-grade chemical carfentanil — so toxic that an amount smaller than a poppy seed can kill a person — is suspected in hundreds of recent drug overdoses in the U.S. and Canada.