Dr. Des Colohan says a senior citizen recently succumbed to fumes from a generator that was operating in a confined space during a power outage.
Colohan did not release further details in a statement issued Wednesday.
He says carbon monoxide at high concentrations can render a person unconscious in as little as three minutes, which is why the gas is known as a "silent killer."
The odourless, colourless gas can also be produced by burning kerosene, furnace oil and charcoal.
Colohan says portable generators should never be used indoors, even if ventilation is provided.