Quick answer
Shelter in place means make the building your protective equipment: everyone inside, doors and windows shut, fans and HVAC off so outside air stays outside, and for chemical events, one interior room sealed with plastic and tape while the radio tells you when it has passed. Most events last hours. The kit is a 3-day home supply plus a roll of plastic sheeting that costs less than pizza.
Supply numbers are set for 4 people. Change your household size below and every quantity updates.
Hours
Typical shelter-in-place duration
HVAC off
The step people forget
1 room
Sealed, interior, above ground for chemicals
10 sq ft
Of floor space per person keeps air fine for hours
How a shelter-in-place actually unfolds
The order
A wireless alert or broadcast: hazardous release, shelter in place, your area. The clock starts on getting everyone and the pets indoors.
Minutes 1 to 10
Doors, windows, HVAC, bathroom fans, dryer: everything that moves air, off and shut. For chemical events, the pre-cut plastic goes over the safe room's door, window, and vents.
The hours
Radio on, snacks out, cards dealt. The building does the protecting; the household's job is patience and not opening things to peek.
The all-clear
Officials lift the order. Then, counterintuitively, you OPEN everything: flush the house with fresh air, because the outside is now cleaner than what seeped in.
Play it out
Six sealed hours, three decisions
A tanker rollover two miles away on a windless morning. Play the stay.
Scene 1 of 3
9:12am. Alert: hazardous materials release, shelter in place immediately, your zone. The kids are home, the dog is in the yard, and your neighbor is outside filming the distant smoke with great interest.
Prefer to read it straight through?
Scene 1
9:12am. Alert: hazardous materials release, shelter in place immediately, your zone. The kids are home, the dog is in the yard, and your neighbor is outside filming the distant smoke with great interest.
If you step out to get a look and compare notes with the neighbor: The two of you get four minutes of vaguely chemical-smelling footage. It is probably harmless at this distance, and probably is doing heavy lifting for a plume you cannot see or judge. You come inside anyway, four minutes later than the dog did.
If you dog in, kids counted, doors shut, hvac off, radio on. two minutes: The house buttons up in the time the alert took to read twice. The forgotten step at most houses, killing the HVAC and bath fans, happens here because it was on the fridge card. Now the building is doing its job and you are on the couch, not the lawn.
Field note: For an airborne release, the protective value is indoors-with-air-handling-off, started immediately. The house leaks slowly; the ventilation system imports outside air fast. Kill the fans first.
Scene 2
9:40am. Radio says the release involves chlorine-family chemicals and zones nearest the site should seal an interior room. You are near the boundary. There is a roll of plastic sheeting and tape in the closet, or there is a lively group chat debating whether sealing is overkill.
If you boundary zone, windless day. the chat says skip the plastic: The chat is probably right, boundary plus distance is real margin. But sealing is a ten-minute task whose whole point is covering the cases where probably misses. You spend the morning refreshing wind maps instead of playing cards.
If you seal the main bedroom: plastic on door, window, and vent. ten minutes: Pre-cut plastic labeled BEDROOM goes up with painter's tape, snacks and the radio move in, and the door seals behind you. If the plume never reaches your street, you spent ten minutes. Insurance is supposed to be slightly silly right up until it is not.
Field note: A sealed interior room adds a strong second layer for chemical events: plastic and tape over door, window, and vents. Ten square feet of floor per person holds fine air for the hours these events last.
Scene 3
1:50pm. All-clear for your zone. Nearly five hours indoors, the kids have invented a card game with unstable rules, and the house feels stuffy in a way you are suddenly aware of.
If you order is lifted, life resumes, windows stay however they are: The house holds onto its five stale hours, including whatever trace amounts seeped in during the peak. Harmless at these levels, but the protocol has one last step for a reason, and skipping it keeps the worst air of the day inside with you.
If you run the flush: every window open, fans on, air the whole house: Twenty minutes of cross-breeze trades the day's accumulated indoor air for the now-clean outside. Plastic comes down, gets binned, and the replacement roll goes on the shopping list because the kit resets today, not someday.
Field note: After the all-clear, the outside air is cleaner than what accumulated indoors: flush the house deliberately. Then restock the tape and plastic while the memory is fresh.
The shelter-in-place checklist
People in your household
One page per scenario: quantities resize in place, and the link you share always shows this plan.
Your head start
0 of 3 days covered
0 of 9 essentials on hand
Tick what you already own.Save this as your real plan →Supplies buy you days. Gear keeps those days livable. Most families discover they start around day 3.
| Item | For 4 people | Why it matters | Covers | |
|---|---|---|---|---|
| The sealing kit | ||||
| Plastic sheeting, pre-cut and labeled | Door, window, vents of one room | Cutting to size during the event is the step that fails. Pre-cut, label, store flat. | Chemical | |
| Painter's tape and duct tape | 2 rolls | Painter's for speed, duct for gaps that fight back. | Chemical | |
| Battery radio in the safe room | 1 | The all-clear comes by zone; the radio is how you hear yours. | Critical | |
| The fridge card: shutdown list | HVAC, bath fans, dryer, fireplace damper | Air handling off is the most-skipped step. A list beats memory at 9am. | Critical | |
| Water · 12 gallons total | ||||
| Bottled water, 24-pack cases | 3 cases (about 7 gal) | Sealed, portable, splits between rooms and the car. | All days | |
| 5-gallon water jugs | 1 jug | The cheapest gallons you can store. Fill spares before the event, not during. | Backup | |
| Water purification tablets | 1 pack | Turns suspect tap or tub water into drinking water after day 3. | Backup | |
| Food, no cooking required | ||||
| Canned protein: tuna, chicken, beans | 8 cans | Eats straight from the can when the stove is out. | No cooking | |
| Canned vegetables and fruit | 9 cans | Fluids and vitamins while the fridge is dark. | No cooking | |
| Peanut butter | 1 large jar | 2,650 calories per jar, no prep, kids will actually eat it. | No cooking | |
| Crackers, tortillas, granola bars | 2 boxes plus a dozen bars | The bread aisle empties first. These keep for months instead of days. | No cooking | |
| Oats and shelf-stable milk | 3 cartons plus a canister of oats | Breakfast without power, and the milk needs no fridge until opened. | No cooking | |
| Health and documents | ||||
| First aid kit | 1 | Minor injuries spike during cleanup, exactly when help is hardest to reach. | All week | |
| Prescription medications | 14-day supply each | Pharmacies reopen slowly. Ask your pharmacist about an emergency refill before you need it. | 2 weeks | |
| Documents in a waterproof bag | IDs, insurance, cash in small bills | ATMs and card readers die with the power. | Grab and go | |
| Manual can opener | 1 | Most of the calories above are locked inside cans without it. | Critical | |
A 3-day home kit covers the long tail; the sealing kit covers the chemical case. Print this page to take it shopping.
In the app
The protocol is short. Keeping it ready is the trick.
Provision Planner has a built-in Shelter in Place scenario: the sealing kit inventory, the 3-day home supply in days for your household, and live emergency alerts so the order and the checklist arrive in the same pocket.
Run the shelter scenarioShelter in Place scenario
Sealing kit
Ready
Water
3 days
Food
5 days
Emergency alerts
Live
Computed from your real inventory. Updates itself as things expire.
Frequently asked questions
When do officials order shelter-in-place instead of evacuation?
When the hazard is fast, airborne, or short-lived enough that travel is riskier than walls: chemical releases, some hazmat and radiological events, and certain police situations. The instruction is hazard-specific, which is why following YOUR zone's order beats copying the next town's.
Does taping a room really do anything?
For chemical events, yes: reducing air exchange is the entire protective mechanism, and plastic over the leakiest surfaces of one room measurably cuts infiltration for the hours that matter. It is short-term protection by design, which is fine, because these events are short.
Will we run out of air in a sealed room?
Not in the timeframes these events run: plan around ten square feet of floor space per person and normal rooms hold comfortable air for several hours. The all-clear almost always arrives long before air quality does anything interesting.
What about pets during shelter-in-place?
They shelter with you, and getting them indoors is part of minute one, which is why leashes and carriers should not require an expedition. A dog's bathroom emergency during a multi-hour order is solved with puppy pads in the garage, not a walk.
Explore more scenarios
Every scenario gets the same treatment: the event, the supplies, the timeline, and your number.
Scenario 19Gas Leak and Carbon Monoxide
Scenario 11Nuclear Attack
Scenario 16Evacuation
Scenario 06Power Outage
Scenario 12Pandemic34 scenarios, one libraryBrowse them all →Go deeper: 3-Day Supply Plan for 4 People · Food Storage Calculator
Shelter-in-place protocol follows Ready.gov and CDC guidance for chemical emergencies. This is general planning guidance: your zone's official instruction always outranks a general page. Photography: NASA image library and Pexels, used under their respective licenses.