Self-Reliance · Shelter
Sometimes the safest place is the building you are already in. Tornado, hazmat release, nuclear event, earthquake, wildfire smoke, volcanic ashfall. Each scenario has a different room, a different posture, and a different duration. Know which is which before the alert sounds.
Shelter or evacuate?The first question
The decision to stay or go depends on what the hazard is, where it is relative to you, and how fast it is moving. Getting this wrong in either direction is dangerous. Evacuating into a tornado or a chemical plume is worse than sheltering. Sheltering during a flood that is rising toward your floor level is worse than leaving early. For a deeper walk-through of this decision, including the four hazard types and a step-by-step framework, see our shelter-in-place decision guide.
The hazard is airborne and moving through your area (chemical spill, nuclear fallout, volcanic ashfall, wildfire smoke). Your building's walls and sealed openings provide better protection than being outside.
The hazard is arriving too fast to outrun (tornado, severe thunderstorm with lightning, earthquake). Movement during the event increases your exposure.
Authorities specifically direct shelter-in-place via weather radio, emergency alert, or local notification.
Authorities order evacuation (mandatory evacuation for hurricane, wildfire, dam failure).
Floodwater is entering or approaching your building. Do not shelter in place on the ground floor of a flooding structure.
Your building has sustained structural damage that makes it unsafe (visible cracks in load-bearing walls, roof collapse, fire damage).
A wildfire is approaching and you have time to leave safely. Wildfire moves faster than most people realize, especially in dry, windy conditions. Leave early rather than waiting to see if it reaches you.
Chemical hazard
A chemical release from a train derailment, industrial accident, or transportation spill can send a toxic plume across a residential area in minutes. Ready.gov's guidance for chemical shelter-in-place is specific: get inside, close everything, seal the room, and wait for the all-clear.
Choose an interior room above ground level. Most chemical vapors are heavier than air and settle into basements and low areas. A room with few windows and doors is easier to seal. A bathroom works well because it is small, has a water supply, and typically has only one door and one small window or none.
Close all exterior doors and windows throughout the house. Turn off HVAC systems, exhaust fans, attic fans, and anything that pulls outside air in. In your shelter room, cover windows and vents with pre-cut plastic sheeting (6-mil poly or heavy garbage bags) and seal all edges with duct tape. Seal the gap under the door with a wet towel. Seal electrical outlets and switch plates with tape. This creates a temporary air barrier that reduces but does not eliminate exposure to outside contaminants.
A sealed room provides protection for approximately 2 to 4 hours before the oxygen in the room becomes the greater concern. Chemical plumes typically pass within this window. Wait for the official all-clear from emergency management before unsealing. When you do unseal, open windows and doors to ventilate the house before resuming normal activity.
Pre-cut and pre-stage
Measure your shelter room now. Pre-cut plastic sheeting for each window and vent. Store the sheeting, duct tape, scissors, and a wet towel in a labeled box in that room. During an actual event, you may have only minutes to seal. Pre-staging reduces the process from 20 minutes to 5. For the full room setup guide, supply list, and quarterly maintenance schedule, see The Shelter-in-Place Room.
Severe weather
A tornado warning means a tornado has been spotted or detected on radar. You have minutes, not hours. The NWS distinguishes between tornado watches (conditions favorable for tornadoes, prepare to act) and tornado warnings (take shelter immediately).
The lowest floor of a sturdy building, in an interior room away from windows. A basement is the best option. If there is no basement, move to an interior closet, bathroom, or hallway on the ground floor. The more walls between you and the outside, the better. Get under a sturdy piece of furniture (a heavy table or desk) and protect your head and neck with your arms, a pillow, or a mattress.
Mobile homes provide almost no protection from tornadoes regardless of age, tie-down systems, or construction quality. The NWS guidance is clear: leave a mobile home and go to the nearest sturdy building or designated tornado shelter. Know where the nearest shelter is before tornado season begins. If no shelter is reachable, lie flat in a low-lying area and cover your head and neck.
The NWS "When Thunder Roars, Go Indoors" guidance applies to any thunderstorm. If you can hear thunder, you are within striking distance of lightning. Move inside a sturdy building or a hard-topped vehicle (not a convertible). Stay away from windows. Do not use landline phones. Stay inside for at least 30 minutes after the last clap of thunder. Lightning kills roughly 20 people per year in the U.S. and injures hundreds more.
Seismic
Earthquakes provide no warning. There is no watch or warning phase. When shaking starts, you respond with what you know and where you are at that moment.
Drop to your hands and knees to prevent being knocked down. Take cover under a sturdy desk or table, positioning yourself so the furniture protects your head and neck. Hold on to the furniture and be prepared to move with it if it shifts. If no cover is available, move to an interior wall away from windows, drop, and cover your head and neck with your arms.
Do not run outside during shaking. Falling debris from building exteriors, power lines, and trees is the primary cause of earthquake injuries outside. Do not stand in a doorway. Modern construction provides no more protection in a doorway than anywhere else in the room, and you are more exposed to swinging doors and falling objects.
Expect aftershocks. They can occur minutes, hours, or days after the initial quake and may be strong enough to cause additional damage. Before moving through the building, check for gas leaks (smell for gas, listen for hissing). If you suspect a gas leak, leave the building and call the gas company from outside. Check for structural damage: cracks in load-bearing walls, shifted foundations, leaning chimneys. If the building appears structurally compromised, leave and do not re-enter until it has been inspected.
Check water lines for breaks. Shut off the water main if you find leaking pipes. Check the electrical panel for damage. If circuits are sparking or you smell burning insulation, shut off the main breaker. For utility shutoff procedures, see our utility shutoff guide.
Radiological
Ready.gov provides specific guidance for nuclear and radiological events. The primary risk after a nuclear detonation or radiological release is radioactive fallout, microscopic particles that settle from the atmosphere onto surfaces, buildings, and ground. The protective action is to put as much mass and distance between yourself and the fallout as possible.
The best shelter has thick, dense walls and a roof: a basement, the interior rooms of a concrete or brick building, or the center floors of a multi-story building (upper floors reduce exposure from ground-deposited fallout, while the roof provides overhead shielding). The worst shelters are vehicles, mobile homes, and wood-frame buildings with no basement.
Ready.gov advises remaining sheltered for at least 24 hours unless authorities direct otherwise. Radioactive fallout loses intensity rapidly: it drops to about 10% of its initial level within 7 hours and to about 1% within 48 hours. The first 24 hours of sheltering provide the greatest protective benefit. Listen to official channels (NOAA Weather Radio, local emergency broadcasts) for instructions on when it is safe to leave.
If you were exposed to fallout before reaching shelter, remove and bag your outer clothing before entering the shelter room. This removes up to 90% of radioactive material on your person. Shower or wash exposed skin with soap and water. Do not use conditioner, which can bind radioactive particles to hair. Blow your nose, wipe your eyelids, and clean your ears. Place contaminated clothing in a plastic bag, seal it, and place it as far from living areas as possible.
Environmental hazards
Wildfire smoke can travel hundreds of miles and affect air quality for weeks. The EPA's Air Quality Index (AQI) measures particulate matter concentration. When AQI exceeds 150 (unhealthy), limit outdoor activity. Above 200 (very unhealthy), stay indoors with windows and doors closed. Run HVAC on recirculate mode if your system has that option. A portable HEPA air purifier in the room where you spend the most time significantly reduces indoor particulate levels. N95 respirators (properly fitted) provide protection if you must go outside.
Volcanic ash is not like wood ash. It consists of tiny, abrasive glass and rock fragments that damage lungs, eyes, engines, electronics, and water systems. During ashfall, stay indoors with windows and doors closed. Seal gaps with damp towels. Wear N95 masks and goggles if you must go outside. Do not drive unless necessary, as ash clogs air filters and damages engines. After ashfall stops, remove ash from roofs carefully (wet ash is extremely heavy and can cause roof collapse) and avoid washing ash into storm drains, which clogs municipal systems.
Landslides move fast and provide little warning. If you live on or below a steep slope and heavy rain, rapid snowmelt, or earthquake activity is occurring, monitor for signs: new cracks in the ground or pavement, tilting trees or retaining walls, unusual sounds (rumbling or cracking from the hillside), and suddenly muddy water in streams or drainage channels. If a landslide is imminent or occurring, move to the highest available floor and away from the downhill side of the building. If outside, move laterally out of the flow path, not downhill. Do not cross flooded or debris-filled areas.
Sanitation
If water service is disrupted or you are sheltering without functional plumbing, sanitation becomes a health priority within hours. Improper waste disposal in a confined space creates disease risk faster than most people expect.
A 5-gallon bucket lined with a heavy-duty garbage bag serves as an emergency toilet. Add a pool noodle or a snap-on toilet seat (available at camping supply stores for $10 to $20) for comfort. After each use, add a scoop of kitty litter, sawdust, or a commercial waste solidifier to control odor and absorb moisture. Tie off full bags, double-bag them, and store them outside the living area until regular waste collection resumes.
Handwashing remains the most important disease prevention measure during any shelter-in-place scenario. If running water is unavailable, use hand sanitizer with at least 60% alcohol content. Stock enough for every household member to sanitize after every bathroom use, before every meal, and after handling waste. A gallon jug of water with a spigot or a camping water container can provide a basic handwashing station.
If the sewer system is compromised (earthquake damage, flood contamination), do not flush toilets. Flushing pushes waste into damaged lines where it can back up into the home or contaminate groundwater. Use the bucket system described above until authorities confirm the sewer system is functional.
Structural
Storm damage may compromise the roof while you are still sheltering. A hole in the roof during continued rain creates cascading problems: water damage to ceilings, walls, and electrical systems, mold growth that begins within 24 to 48 hours, and loss of insulation value.
If you can safely access the attic or upper floor, contain the water with buckets, tarps on the floor, or towels. Do not attempt exterior roof work during active storm conditions (rain, wind, lightning). After the storm passes and conditions are safe, a temporary tarp over the damaged area prevents further water intrusion until a professional roofer can make permanent repairs.
For detailed tarping procedures and safety guidelines, see the emergency repair section of our Home Repair Basics guide.
Go deeper
This page covers the scenarios. These two guides cover the decision framework and the room itself.
The four hazard types, how alerts reach you, the stay-or-go decision framework, and the difference between shelter-in-place, evacuation, and lockdown.
How to choose the right room, the five supply categories with cost estimates, the sealing procedure for chemical events, and the quarterly maintenance schedule.
Sewer gas from dry drain traps, mold from condensation, CO2 from combustion heating, and how to ventilate safely during an extended power outage.
Next steps
Most likely scenario
Identify your tornado shelter room. Stock a weather radio. Make sure everyone in the household knows where to go when a warning sounds.
Tornado and stormsIndustrial or chemical risk
Pre-cut plastic, stage duct tape, and identify your interior room. If a chemical release happens near you, this preparation turns 20 minutes of scrambling into 5 minutes of action.
Set up the room