Generator exhaust is toxic. Always put generators outside well away from doors, windows, and vents. Carbon monoxide (CO) is deadly, can build up quickly, and linger for hours. More information
Combustion appliances are those which burn fuels for warmth, cooking, or decorative purposes. Typical fuels are gas, both natural and liquefied petroleum; kerosene; oil; coal; and wood. Examples of the appliances are space heaters, ranges, ovens, furnaces, woodburning stoves, fireplaces, water heaters, and clothes dryers. These appliances are usually safe. However, under certain conditions, these appliances can produce combustion pollutants that can damage your health, or even kill you.
Possible health effects range from headaches, dizziness, sleepiness, and watery eyes to breathing difficulties or even death. Similar effects may also occur because of common medical problems or other indoor air pollutants.
A properly installed, correctly used wood-burning appliance should be smoke free. If you see or smell smoke that means you may have a problem. Never burn household garbage, colored paper or ink, or any type of plastic, foam, or other artificial materials. Burning these can release harmful chemicals. Practice these guidelines to Burn Wise.
Article Source: http://www.epa.gov/epahome/hi-winter.htm