Trenton, NJ — Five people including a toddler were hospitalized after being exposed to a dangerous level of carbon monoxide Thursday night.

First responders in Trenton were called to a rental house on North Olden Avenue about several people being sick, according to city spokesman Tim Carroll. A Hazardous Materials Team was brought in and measured an extremely high level of carbon monoxide of roughly 600 parts per million, according to Carroll.

The source of the carbon monoxide was a gas-powered generator in the basement. Authorities did not say why the house was using a generator.

Authorities did not say whether the apartment had a working carbon monoxide detector.

Carroll said four adults and a three-year-old child were transported to Capital Health.

A CO level above 400 can be life-threatening with a risk of death after 3 hours of exposure, according to detector manufacturer FirstAlert. Symptoms of exposure include hallucinations, dementia and serious headaches.

Flown to a specialized hospital

Peterson’s Breaking News of Trenton posted video of a medical helicopter flying one of the victims to Jacobi Hyperbaric Medical Center in the Bronx.

Jacobi has the only walk-in hyperbaric chamber in the New York metropolitan area and has treated over 3,000 patients with carbon monoxide poisoning since opening in 1983, according to the hospital website.