Smoke Inhalation First Aid: Warning Signs, What to Do After a Fire and Why Symptoms Can Show Up Later

Quick answer: get the person away from the smoke and into fresh air without putting yourself in danger, then call 911. Smoke can contain carbon monoxide and other toxic gases and can injure the airway with heat. Anyone with trouble breathing, hoarseness, coughing up soot, burns around the face, confusion, headache or drowsiness needs emergency care, even if they seem to improve, because airway swelling and poisoning can get worse over the next several hours. If they stop breathing, start CPR.

Most deaths in home fires are caused by smoke and toxic gases rather than burns, according to fire safety organizations such as the National Fire Protection Association (NFPA). Smoke spreads fast in apartment buildings through hallways, stairwells and shared ventilation, which means residents can be exposed even when the fire is several floors away.

This article is part of our emergency first aid guide for city households. It explains what smoke does to the body, the signs to watch for, first aid steps and how to reduce your risk in an apartment fire. It is general safety information, not medical advice.

Sources: National Fire Protection Association (NFPA) fire safety and high-rise guidance; U.S. Fire Administration (USFA) home fire safety resources; Centers for Disease Control and Prevention (CDC) information on carbon monoxide poisoning; MedlinePlus (National Library of Medicine) information on smoke inhalation; UL Fire Safety Research Institute “Close Before You Doze” campaign. Checked November 2026. In an emergency, call 911.

What Smoke Does to the Body

Smoke from a fire is a mix of hot gases, tiny particles and chemicals. It can harm you in several ways at the same time.

Heat injury to the airway

Breathing very hot air or steam can burn the mouth, throat and upper airway. Swelling from these burns can narrow the airway, sometimes over several hours.

Carbon monoxide

Carbon monoxide (CO) is a colorless, odorless gas produced when materials burn. It binds to red blood cells more readily than oxygen, so the body’s organs do not get enough oxygen. The CDC lists headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion as common symptoms of CO poisoning. High levels can cause loss of consciousness and death.

Other toxic gases

Burning plastics, foams and synthetic fabrics, which are common in modern homes, can release other toxic gases, including hydrogen cyanide. These can also interfere with the body’s use of oxygen.

Irritants and particles

Smoke contains soot and irritating chemicals that can inflame the lungs and airways. This can cause coughing, wheezing and shortness of breath, and it can make asthma or other lung conditions worse.

Signs of Smoke Inhalation

Watch for these signs in anyone who has been in or near a fire:

• Coughing, especially coughing up black or gray mucus
• Shortness of breath, fast breathing or wheezing
• A hoarse voice or noisy breathing
• Soot in or around the nose and mouth
• Singed nose hairs or eyebrows, or burns on the face
• Headache, dizziness or nausea
• Confusion, drowsiness, agitation or fainting
• Red, irritated eyes
• Chest pain

Any of these signs after smoke exposure is a reason to get medical care. Hoarseness, noisy breathing, soot in the mouth or facial burns can point to airway injury, which can become life-threatening as swelling develops.

Step 1: Make Sure It Is Safe

Do not go into a smoke-filled area to rescue someone. Smoke can overcome rescuers quickly, and firefighters have breathing equipment and protective gear. Call 911 and tell the dispatcher where the person is.

If you are already in a safe position and can reach the person without entering smoke, help them move to fresh air outside or to a clear area away from the fire.

Step 2: Call 911

Call 911 for anyone who has breathed in smoke and has symptoms. Tell the dispatcher:

• That the person was exposed to smoke in a fire
• Their symptoms, especially trouble breathing, confusion or unresponsiveness
• Your exact location, including building entrance, floor and unit if relevant

Even if the person feels okay at first, a medical check is important. Symptoms of airway injury and CO poisoning can be subtle or delayed.

Step 3: Check Breathing and Response

Once the person is in fresh air:

• Check whether they respond when you speak to them and tap their shoulder.
• Watch their chest to see whether they are breathing normally.

If the person is not breathing normally, start Hands-Only CPR right away and continue until help arrives or they start breathing. Use an AED if one is available.

If they are breathing but drowsy or unresponsive, place them on their side to keep the airway open, and keep watching their breathing.

If they are awake and breathing, help them sit up in a comfortable position, which often makes breathing easier. Loosen tight clothing around the neck and chest.

Step 4: Treat Burns and Other Injuries

If the person has burns, cool them with cool, not icy, running water for about 20 minutes and cover them loosely with a clean, non-stick dressing or plastic wrap. Do not apply butter, oils or ice. Our guide to burn first aid explains these steps in more detail.

Rinse irritated eyes gently with clean water. Remove clothing that has been soaked with smoke or chemicals if it can be done without causing pain or further injury.

Step 5: Stay With the Person

Stay with the person until emergency responders take over. Watch for worsening symptoms, such as increasing difficulty breathing, a change in voice or more confusion. Tell responders what you have seen and how long the person was exposed, if you know.

Why Symptoms Can Be Delayed

People sometimes leave a fire scene feeling fine and become ill later. There are several reasons:

• Swelling in the airway from heat injury can increase over the hours after exposure.
• Lung irritation can worsen over the next day or two.
• CO poisoning can cause symptoms that are mistaken for tiredness or a headache.

For these reasons, MedlinePlus and emergency medicine guidance recommend medical evaluation for people with symptoms after smoke exposure. Seek emergency care right away if someone develops trouble breathing, chest pain, confusion or a persistent cough after a fire, even if they were checked earlier.

Who Is at Higher Risk

Some people are more vulnerable to smoke:

• Young children, whose airways are smaller and who breathe faster
• Older adults
• People with asthma, COPD or heart disease
• Pregnant people, since CO can affect the fetus
• Pets, which can also suffer from smoke inhalation and should be checked by a veterinarian

Lowering Your Risk in an Apartment Fire

Prevention and preparation can make a large difference.

Working smoke alarms

Smoke alarms give early warning, which is your best chance to escape before smoke builds up. The NFPA recommends smoke alarms inside each bedroom, outside each sleeping area and on every level of a home. Test them monthly. Our guide to smoke alarm placement and testing explains the details.

Carbon monoxide alarms are also important, especially if your building has fuel-burning appliances or an attached garage.

Know your building’s plan

Apartment buildings have different fire plans depending on their design and fire protection systems. Some buildings are designed for residents to evacuate; others, especially high-rises with sprinklers and fire-resistant construction, may instruct residents to stay in their units unless the fire is in their unit or smoke is entering. Ask your building management about the plan, and read any notices posted in your building. Our guide to making an apartment fire safety plan walks through how to prepare.

Close doors

Closed doors slow the spread of smoke and fire. Research from the UL Fire Safety Research Institute, promoted through its “Close Before You Doze” campaign, has shown that a closed bedroom door can keep temperatures and smoke levels in a room much lower during a fire. Sleeping with bedroom doors closed and closing doors behind you as you leave a burning apartment are simple, effective steps.

Get low under smoke

Smoke and heat rise. If you must escape through smoke, stay low, crawling if necessary, where the air is clearer and cooler.

Check doors before opening

Before opening a door during a fire, feel the door and the doorknob with the back of your hand. If they are hot, do not open the door. Use another way out or stay in the room.

If you are trapped

If you cannot leave safely:

1. Close the doors between you and the fire.
2. Seal gaps under doors and around vents with towels, blankets or tape.
3. Call 911 and tell the dispatcher exactly where you are, including the apartment number and floor.
4. Signal from a window with a bright cloth or flashlight if it is safe to do so.
5. Open a window slightly for fresh air if smoke is not coming in from outside, and be ready to close it if smoke enters.

Never use elevators

During a fire, use stairs, not elevators, unless the fire department tells you otherwise. Elevators can stop working or open onto a floor filled with smoke.

Teaching Children What to Do

Children may hide during a fire, under beds or in closets, because they are frightened. The U.S. Fire Administration encourages families to teach children fire safety in simple, practical ways:

• Practice what the smoke alarm sounds like, so children know it means “get out.”
• Teach them to get low and go under smoke.
• Show them how to feel a door with the back of the hand before opening it.
• Make sure they know two ways out of each room, if your apartment allows.
• Choose a meeting spot outside the building where everyone gathers.
• Teach them never to go back inside for toys or pets.

Practice your escape plan at least twice a year, including at night. In an apartment, include the route to the nearest stairwell and a backup route.

Smaller Smoke Exposures at Home

Not every smoke exposure comes from a large fire. Burnt food, a small kitchen flare-up or a smoldering appliance can fill a small apartment with smoke quickly.

If this happens:

• Turn off the heat source if you can do so safely.
• Cover a small pan fire with a lid and leave it covered. Never pour water on a grease fire.
• Open windows and use a range hood to clear the air.
• Leave and call 911 if the fire grows, if you cannot put it out right away, or if smoke keeps building.

Even small amounts of smoke can trigger asthma symptoms. Anyone who has trouble breathing, chest tightness or a persistent cough afterward should follow their asthma plan and seek care if symptoms do not improve.

After the Fire

After a fire, smoke and soot can linger in your home. Stay out until fire officials say it is safe to return. When you go back:

• Air out the space by opening windows if conditions allow.
• Avoid stirring up soot and ash, which can irritate the lungs.
• Discard food, medicine and cosmetics exposed to smoke, heat or firefighting water.
• Watch for lingering symptoms such as coughing, headaches or breathing problems, and seek medical care if they appear.

Fires can be traumatic. Talking to friends, family or a counselor can help, and many communities offer support after disasters.

Frequently Asked Questions

How long after smoke inhalation can symptoms appear?

Some symptoms appear right away, but airway swelling and lung irritation can get worse over hours or even a day or two after exposure. Seek medical care if symptoms develop or worsen.

Should I go to the hospital after breathing in smoke?

Anyone with trouble breathing, hoarseness, coughing up soot, burns around the face, confusion or headache after a fire should get emergency care. Even mild symptoms are worth a medical check.

Can smoke inhalation cause carbon monoxide poisoning?

Yes. Fires produce carbon monoxide, which can cause headache, dizziness, confusion and loss of consciousness. CO is colorless and odorless, so you cannot detect it without an alarm.

Does a wet cloth over the face protect against smoke?

A cloth may block some particles, but it does not filter out carbon monoxide or other toxic gases. Getting out quickly and staying low is more important.

Can pets get smoke inhalation?

Yes. Pets can be harmed by smoke in the same ways as people. If a pet was exposed to smoke, contact a veterinarian promptly.