* Every year, have a professional check appliances that burn fuel to make sure they're ventilated and working properly.
* Don't use a gas oven to heat your home -- even if it's just for a few minutes.
* Never use a charcoal grill, which produces CO, in the fireplace or anywhere else inside the house.
* Make sure the flues are open when you use your fireplace.
* Warm up your car outside instead of in the garage, where fumes can build up quickly. (If you have an attached garage, CO can even travel into the house.)