From approximately Dec. 22 to New Year's Day firefighters received 574 carbon monoxide-related calls, or four times the amount received during the same time last year.
Julie Reid called 9-1-1 after her detector went off indicating the CO level in her house was high enough to cause intense headaches, or even brain damage.
The cause was a gas fireplace in Reid's basement that malfunctioned when the power went out a few days before Christmas.
Fire crews also told her that the detector, which was made in 2002, no longer worked.
Acting District Chief George Warner said one mistake people make is not knowing when their CO detector needs to be replaced.
"Look at the instructions on the back of the packages," he said, noting the label should indicate how many years the detector is good for.
Warner also said people should only buy carbon monoxide detectors that have been tested to Canadian standards, and they will have a Underwriters Laboratories of Canada and or a Codes & Standards stamp on the back of the device.