Carbon monoxide: check your alarms as the furnace kicks on

Colorado Springs winters mean furnaces, fireplaces, gas water heaters and cars warming up in the garage. All of them can make carbon monoxide (CO), a gas you can't see or smell. Each year in the U.S., more than 400 people die from CO poisoning not caused by fires, more than 100,000 go to an emergency department, and more than 14,000 are hospitalized.

Why it's easy to miss

The symptoms of CO poisoning are headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion. That list looks a lot like the flu, which is why CO poisoning gets missed, especially in winter.

Clues that point to CO rather than a virus:

• Several people in the house, or the pets, feel sick at the same time.
• Symptoms improve when you're away from home and come back when you return.
• Symptoms started when the heat came on, or after the furnace, fireplace or a generator was running.

People who are asleep or have been drinking can be badly poisoned before they notice anything. Babies, older adults and people with heart disease, anemia or breathing problems are affected sooner, at lower levels.

What Colorado law requires

Colorado requires a working CO alarm within 15 feet of the entrance to each bedroom in homes that have a fuel-burning heater or appliance, a fireplace, or an attached garage. The rule applies when a home is sold or remodeled with a building permit, and rental units must have alarms when a new tenant moves in. Even if your home hasn't been sold or rented recently, the protection is the same, so follow it anyway.

Five habits for the winter

• Alarms near every sleeping area and on every level. Use battery-powered alarms or plug-in alarms with a battery backup, and test them once a month.
• Change the batteries when the clocks change. Clocks fall back on Sunday, November 1, which makes this weekend a good reminder. Replace the alarm itself on the maker's schedule, or about every five years.
• Service the furnace every year. Have a qualified technician check gas, oil or wood heating equipment and the chimney or flue.
• Never run an engine inside, even with the garage door open. If you warm up the car, back it out of the garage right after starting it, and keep snow clear of the tailpipe.
• Clear vents after snowstorms. Snow can block the outside vents for the furnace, dryer and water heater. Grills and generators belong outdoors, well away from windows and doors.

If the alarm goes off

Get everyone, including pets, outside into fresh air right away. Then call 911 from outside. Don't go back in until firefighters say it's safe. Anyone with symptoms should be checked in an emergency department, since CO poisoning can need oxygen treatment.

Sources: Centers for Disease Control and Prevention. Carbon monoxide poisoning basics. cdc.gov. Colorado Springs Fire Department. Carbon monoxide safety. coloradosprings.gov. Colorado Revised Statutes §§ 38-45-103 and 38-45-104. colorado.public.law.