The Brevard County Sheriff's Office is investigating at least 11 overdoses that resulted in one death in Cape Canaveral and Merritt Island.
The victims appeared to have taken a combination of traditional heroin and Fentanyl, which authorities believe may have been from the same batch.
Fentanyl is typically used in easing extreme pain for some end-stage cancer patients.
Major Todd Goodyear said the unidentified Cape Canaveral man was found in his home and was a known heroin user.
Florida Today reports some of the victims said they were snorting it.
Investigators are also awaiting a toxicology report in the fatal case to determine if other drugs, alcohol or an underlying medical condition may have contributed to the death.
The overdoses occurred on Monday.