Update for Weeks 50 and 51 (December 7–20, 2009):

• Weather conditions, characterized by low temperatures, likely accounted for the increase in the weekly number of reported carbon monoxide (CO) poisoning incidents, observed mainly during week 51;

• Two deaths were reported to the surveillance system: the first was linked to the operation of a motor vehicle in a closed garage, and the second was intentional,

• Five incidents of mass CO poisoning occurred in public places such as a school, a store, a community center, or a restaurant. One of the incidents, which occurred in a restaurant, was associated with the use of a generator in an enclosed space.