Tecumseh fire crews have been busy the first week of January due to a spike in the number of carbon monoxide detectors sounding off.
Fire Prevention Officer Bob Hamilton says so far this year, about 50% of the calls it has responded to are CO related.
Hamilton says it is great to see people are investing in a CO detector, but he says people must also maintain their appliances including the alarms.
Hamilton says once the CO detector beeps, home owners need to invest in a new one. He says there are several reasons why the CO alarms goes off.
"We get a lot that are that have reached their life span or have been defective or there is a problem with the furnaces or appliances that are being controlled by gas."
Most homes have been shut tight the last few weeks because of the frigid temperatures which can cause a build-up of CO if the furnaces are not properly maintained.
He says that build-up can kill.
"It is serious. People have to recognize what is going on in their own home, with the appliances that they are going, with the alarms, they have to be more cognizant of checking those things on a monthly basis."
Carbon monoxide is a toxic, odourless gas that can be deadly. Symptoms of carbon monoxide include headaches and feeling nauseous.
One person was taken to the hospital for observation on Saturday after the CO detector went off.
A new law in October 2014 requires every home with a fuel burning appliance, fireplace or attached garage have a working carbon monoxide alarm.