Carbon Monoxide
An odorless, colorless gas produced when fuel burns, and the leading post-storm and post-fire safety hazard in a damaged building.
The short version
- CO is odorless and colorless, so it cannot be detected without an alarm.
- CDC identifies the most common symptoms as headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion, often described as flu-like.
- People who are sleeping or under the influence can die from CO poisoning before they have symptoms.
- Generators must be used outside only, more than 20 feet from windows, doors, and vents.
- Never run a generator, grill, camp stove, or vehicle inside a home, garage, or crawl space.
What it actually means
Carbon monoxide is produced whenever fuel is burned, and after a storm or a fire it becomes the most immediate life-safety hazard in a damaged property. CDC describes it as an odorless, colorless gas that can cause sudden illness and death, and which is entirely preventable. The danger is that there is no sensory warning: you cannot smell it or see it, and the early symptoms resemble ordinary illness.
The symptom list matters because people misread it. CDC identifies headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion as the most common effects, and notes they are often described as flu-like. Breathing in a large amount can cause loss of consciousness or death. Critically, CDC warns that people who are sleeping, drunk, or under the influence of other substances can die from CO poisoning before they ever have symptoms, which is why alarms rather than awareness are the control.
The scenario that produces most post-disaster poisonings is a portable generator during a power outage. CDC guidance is unambiguous: use generators outside only, more than 20 feet away from any windows, doors, and vents, and never in a home, basement, garage, or crawl space, even with doors and windows open.
What it looks like on a real job
After a hurricane or a fire, the safety checklist we walk homeowners through starts here: working CO alarms on every level, generators outdoors and well away from openings, no fuel-burning appliance used indoors for heat or cooking, and no vehicle idling in an attached garage.
If an alarm sounds or anyone in the household develops those symptoms, the response is to get everyone into fresh air immediately and call 911 from outside. Do not go back in to investigate, ventilate, or retrieve anything.
Questions we get asked
- Can I smell carbon monoxide?
- No. It is odorless and colorless, which is exactly what makes it dangerous. A working CO alarm is the only reliable way to know it is present, and there should be one on every level of the home.
- How far from the house does a generator need to be?
- CDC guidance is to use generators outside only and more than 20 feet away from any windows, doors, and vents. Never in a garage, basement, crawl space, or any enclosed or partially enclosed area, regardless of ventilation.
- What should I do if the CO alarm goes off?
- Get everyone outside into fresh air immediately and call 911 from outside. Do not re-enter to open windows or find the source. Treat flu-like symptoms that improve when you leave the building as a possible CO exposure and seek medical attention.
Official sources
Everything on this page rests on the documents below. Read them yourself, they are all free.
- CDC, Carbon Monoxide Poisoning Basics
- CDC, Generator Safety Fact Sheet
- CDC, Prevent Carbon Monoxide Poisoning after a disaster
- Ready.gov, Hurricanes
Last reviewed against these sources on August 26, 2026. These definitions are general information about restoration work and property claims in Florida, not legal advice or a coverage opinion. Your policy language and the facts of your loss control what is owed. Swift Response Restoration Inc is a licensed restoration contractor, not an insurer, a public adjuster, or a law firm.
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Related terms
Fire Damage
Four kinds of damage stacked on one event: what burned, what the smoke reached, what the suppression water did, and what happened to the contents.
Wind Damage
Structural damage from high winds, which matters most for what it opens up: once the envelope is breached, water does the rest.
Emergency Board-Up and Tarping
Temporary protection, roof tarps, board-up, and shoring, put in place immediately to stop further damage while permanent repairs are arranged.
Indoor Air Quality
The condition of the air inside a building, which after any loss is driven by moisture, particulate, and whatever the HVAC system is circulating.