4 Ways to Guard Against Carbon Monoxide

Some steps to take to protect yourself from exposure to the odorless, colorless, poisonous gas:

• Install carbon monoxide detectors. The standard rule of thumb is one per floor, says carbon monoxide expert Allison Stock, of the National Center for Environmental Health. Place one near the bedrooms. To ensure protection during a power outage, keep battery backups in the plug-in kind of monitor. Since the monitors can wear out, check the expiration date stamped. If the alarm sounds, leave the house and call 911.

• Schedule maintenance. Home heating systems and all gas-burning appliances should be inspected on a yearly basis, Stock says. Chimneys should be cleaned, and boilers maintained. Faulty heating systems are the No. 1 cause of death from nonfire-related accidental carbon monoxide poisoning.

• Be careful with generators. Increasingly used during power outages, gas-powered generators are designed to be placed outside, away from the home. They've been linked to surges in poisoning cases after natural disasters like Hurricane Katrina, says Selim Suner, director of emergency preparedness and disaster medicine at Rhode Island Hospital's department of emergency medicine.

• Take precautions with vehicles. Warm up a car outdoors, never in the garage. And unless the engine's off, avoid swimming behind a boat.

If symptoms such as headache, dizziness, chest pain, or nausea appear, or if you suspect you've been poisoned, seek medical attention.