Daylight Saving Time ends on Sunday, November 6th, 2011.

As people in the United States prepare set their clocks back one hour, the Centers for Disease Control and Prevention stressed the importance of preventing carbon monoxide (CO) poisoning by changing the batteries of CO detectors.

Time reverts to standard time at 2 a.m. on Sunday, as established by the Energy Policy Act of 2005.

"As you prepare to set your clocks back one hour, remember to change the batteries in your CO detector," the CDC said Friday.

"When power outages occur during emergencies such as hurricanes or winter storms, the use of alternative sources of power for heating, cooling, or cooking can cause carbon monoxide to build up in a home, garage, or camper and to poison the people and animals inside," the CDC said.

According to the CDC, over 400 people die every year in the U.S. due to unintentional, non-fire related CO poisoning.
The price of CO detectors ranges from $17 to $50 dollars, according to the online store of a leading home improvement retailer.

The most common symptoms of CO poisoning are headaches, dizziness, weakness, nausea, vomiting, chest pain, and confusion. People who are sleeping or who have been drinking alcohol can die from CO poisoning before ever having symptoms.

7 Ways to Prevent CO poisoning

1. Do have your heating system, water heater and any other gas, oil, or coal burning appliances serviced by a qualified technician every year.

2. Do install a battery-operated CO detector in your home and check or replace the battery when you change the time on your clocks each spring and fall. If the detector sounds leave your home immediately and call 911.

3. Do seek prompt medical attention if you suspect CO poisoning and are feeling dizzy, light-headed, or nauseous.

4. Don't use a generator, charcoal grill, camp stove, or other gasoline or charcoal-burning device inside your home, basement, or garage or near a window.

5. Don't run a car or truck inside a garage attached to your house, even if you leave the door open.

6. Don't burn anything in a stove or fireplace that isn't vented.

7. Don't heat your house with a gas oven.