Carbon Monoxide Safety: Symptoms, Detector Placement, and Generator Rules

Carbon Monoxide Safety for Older Adults and Their Families

When to call 911

If your CO alarm sounds, or you suspect carbon monoxide poisoning, get outside to fresh air right away, then call 911.[2]

• Get everyone out, including pets.
• Don't go back inside until emergency responders say it is safe.

Key takeaways

• Carbon monoxide (CO) has no color and no smell. You can't tell it's there without an alarm.[1]
• Symptoms are often called "flu-like": headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion.[1]
• Older adults and people with heart disease, anemia, or breathing problems are more likely to get sick from CO.[1]
• Put battery or battery-backup CO alarms near every sleeping area and on every level of the home.[1][2]
• Never run a generator, grill, or car inside a home or garage, even with doors open.[1][2]

Why it matters

Each year, more than 400 Americans die from unintentional CO poisoning not linked to fires, more than 100,000 visit an emergency department, and more than 14,000 are hospitalized.[1] CPSC estimates that more than 200 of these yearly deaths are tied to consumer products, and more than 100 of those to portable generators.[2]

People who are asleep, or under the influence of alcohol or other substances, can die from CO before they notice any symptoms.[1] That's why an alarm matters more than your nose.

Where CO comes from

CO forms any time fuel burns: cars and trucks, small engines, stoves, lanterns, grills, fireplaces, gas ranges, and furnaces.[1] It can build up indoors.[1]

CO alarms: where, what kind, how long

Tip from CDC: set a phone calendar reminder for the replacement date on the day you install the alarm.[1]

For an older parent, make sure the alarm is loud enough to wake them, and that they know what it sounds like.

Home appliances and heating

From CDC:[1]

• Have your furnace, water heater, and other gas, oil, or coal appliances serviced by a qualified technician every year.
• Have your chimney checked or cleaned every year.
• Make sure gas appliances are vented properly.
• Never heat your home with a gas oven.
• Don't burn anything in a stove or fireplace that isn't vented.
• Never burn charcoal indoors, and don't use portable camp stoves or flameless chemical heaters indoors.
• If your gas refrigerator gives off an odor, have it serviced.

Portable generators

Power outages after storms are a common time for CO poisoning.[2]

• Never use a generator inside a home or garage, even with doors and windows open.[1][2]
• Use it outside only, more than 20 feet from windows, doors, and vents.[1] CPSC adds: point the exhaust away from the home.[2]
• Use a CO alarm inside whenever a generator is running.[1]

Cars and garages

• Never run a car inside an attached garage, even with the door open.[1]
• Have a mechanic check the exhaust system every year.[1]
• If you drive with the tailgate open, open the vents or windows so air moves through.[1]

Know the symptoms

A clue: if several people (or pets) in the same home feel sick at the same time, or feel better after leaving, think about CO.

A quick family checklist

• CO alarm near each bedroom and on every level

• Replacement date on the calendar

• Batteries checked at each clock change

• Furnace, water heater, and chimney checked this year

• Generator plan: outdoors, 20+ feet away

• Everyone knows: alarm sounds → get out → call 911

• Home safety checklist for seniors

FAQ

Where should a carbon monoxide detector be placed? CDC says near every sleeping area. CPSC says on every level of the home and outside sleeping areas.[1][2]

How long do CO detectors last? Replace them according to the manufacturer's instructions or every 5 years, per CDC.[1]

What are the first signs of carbon monoxide poisoning? Headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion, often mistaken for the flu.[1]

Can I run a generator in the garage with the door open? No. Never use one indoors or in a garage. Keep it outside, more than 20 feet from windows, doors, and vents.[1][2]

Sources

1. Centers for Disease Control and Prevention. Carbon Monoxide (CO) Poisoning Basics. CDC. Updated October 26, 2026. https://www.cdc.gov/carbon-monoxide/about/index.html. Accessed October 30, 2026.
2. U.S. Consumer Product Safety Commission. Carbon Monoxide Information Center. CPSC. n.d. https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Carbon-Monoxide-Information-Center. Accessed October 30, 2026.

Disclaimer

This article is for general education only and is not medical, legal, or financial advice. Talk to your doctor, a licensed attorney, or a SHIP counselor (Medicare) about your situation. In an emergency, call 911.

Attribution

Portions of this page are adapted from "HowToLiveBetter" (高性价比人生指南) by eternity4719, https://github.com/eternity4719/HowToLiveBetter, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Changes: topic and evidence approach adapted from Chapters 01 and 13 (gas and carbon monoxide poisoning); rewritten for the U.S. context and re-sourced to U.S. research and official guidance. Not a direct translation.