Disaster preparedness is the practice of equipping your household, home, and vehicle to survive and recover from natural and man-made emergencies with minimal reliance on outside help. The most effective plans are built around your location's real risks — the hazards that actually strike your ZIP code, whether that means hurricanes along the Gulf Coast, wildfires across the Mountain West, earthquakes on the West Coast, ice storms in the Northeast, or flash flooding along inland rivers.
A complete preparedness plan rests on five pillars: knowing your risks, building a supply kit, making a family communication plan, protecting critical documents, and choosing the right backup power for your needs. This glossary defines the core terms every household should understand before an emergency — from "go-bag" and "bug-out plan" to "standby generator," "portable power station," and "shelter-in-place" — so you can read government alerts, product specifications, and insurance paperwork with confidence. Each entry includes a plain-language definition, the preparedness category it belongs to, where in the United States it matters most, and how urgent it tends to be for the average household.
Preparedness is not a one-time checklist but an ongoing habit: rotate water and food supplies, test your generator seasonally, refresh contact lists, and re-evaluate your risks whenever you move or your household changes. Bookmark this glossary and revisit it each season as you build out your own plan.
Emergency Prescription Supply
An emergency prescription supply is at least a seven-day buffer of every medication your household takes, kept current and packed with copies of the prescriptions. Ask your doctor or pharmacist about an early refill or vacation override before storm and fire season, and store medications in a waterproof bag with a written list of dosages, prescribers, and allergies. Pharmacies close and roads flood during disasters, so the buffer is what keeps a chronic condition from becoming an emergency.
HealthCritical priorityAll US
Wireless Emergency Alerts (WEA)
Wireless Emergency Alerts are short, government-issued messages sent to cell phones in a specific geographic area, covering tornado and flash-flood warnings, evacuation orders, AMBER alerts, and presidential messages. They arrive automatically with a distinct tone and do not require an app or a subscription, but the phone must be powered on and connected to a cell tower. Keep emergency alerts enabled in your phone settings and charge your phone ahead of a storm, because a WEA may be your first warning.
CommunicationHigh priorityAll US
Safe Room
A safe room is a small, reinforced interior space built or adapted to protect occupants from extreme wind and flying debris during a tornado or hurricane. It has no windows, is anchored to the structure, and is ideally below ground or on the lowest floor, though an interior bathroom or closet can serve when no purpose-built shelter exists. A safe room should hold thick-soled shoes or helmets, water, a flashlight, and a NOAA weather radio.
ShelterCritical priorityTornado Alley, Gulf & Atlantic coasts
Carbon Monoxide Poisoning
Carbon monoxide is a colorless, odorless gas produced by fuel-burning equipment such as portable generators, grills, and camp stoves, and it kills people every year during outages. Symptoms begin as headache, dizziness, and nausea and progress quickly to confusion and loss of consciousness, so anyone feeling unwell near a running generator should get to fresh air and call 911. Never run a generator, grill, or propane heater indoors, in a garage, or within 20 feet of a window, door, or vent.
HealthCritical priorityAll US
Automatic Transfer Switch (ATS)
An automatic transfer switch is the device that senses a utility outage and switches your home's circuits over to a standby generator within seconds, then switches back when grid power returns. It also isolates your generator from the grid, which protects utility workers from backfeed and is required by electrical code. Households with medical equipment, well pumps, or sump pumps rely on the transfer switch to make that change without anyone being home.
PowerHigh priorityAll US
Peak Load vs. Running Watts
Running watts are the power an appliance draws while it operates normally, while peak (or surge) watts are the brief, much higher draw it needs at startup. A refrigerator might run at 150 watts but surge past 1,200 when its compressor kicks on, and well pumps, furnaces, and air conditioners can be several times higher still. Sizing a generator or power station on running watts alone is the most common reason a backup system trips the moment a motor starts.
PowerHigh priorityAll US
Out-of-Area Contact
An out-of-area contact is a single person, usually living outside your region, whom every household member calls or texts to check in when local networks are overloaded. Long-distance calls and texts often get through when local service is saturated, so the contact acts as a message relay: each person reports in, and the contact tells everyone else who is safe. The name and number should be printed and carried by every member, not just saved in a phone.
CommunicationCritical priorityAll US
Defensible Space
Defensible space is the cleared buffer around a home that slows an approaching wildfire and gives firefighters a place to work. It is usually described in two zones: roughly the first five feet immediately around the structure, where nothing flammable should sit, and the next 30 to 100 feet, where grass, brush, and tree limbs are thinned and ladder fuels removed. Defensible space is one of the strongest factors in whether a house in a wildfire corridor survives.
ShelterHigh priorityMountain West & wildfire corridors
Flood Zone
A flood zone is a FEMA-designated area mapped by its risk of flooding, with letters like A, AE, and X marking how likely and how severe flooding is. Zones beginning with A or V are high-risk and typically require federally backed flood insurance for a mortgage, while Zone X is lower risk but still floods in heavy rain. Your zone determines your insurance cost, your building requirements, and how quickly you may be asked to evacuate.
EvacuationHigh priorityAll US
ERCOT
The Electric Reliability Council of Texas operates the state's independent power grid, covering roughly 90 percent of Texas. Because it has only limited connections to the national grids, ERCOT cannot import large amounts of power when demand spikes in extreme heat or cold, which is why Texas has seen both winter blackouts and summer conservation alerts. Texans should plan for outages that arrive suddenly and can last days, especially during heat waves and hard freezes.
PowerHigh priorityTexas
Water Rotation
Water rotation is the habit of replacing stored drinking water on a schedule, typically every six to twelve months, so your supply stays safe and palatable. Even water stored in food-grade containers slowly picks up taste and odor from the plastic, and any container opened during an emergency should be treated or re-stored rather than left sitting out. Rotate on an easy cue, such as when you change your smoke-alarm batteries, so it actually happens.
Water & FoodHigh priorityAll US
Bug-Out Plan
A bug-out plan is the written half of your go-bag: where you will go, which routes you will take, and what triggers you to leave. It names a primary and a backup destination, at least two driving routes that avoid the hazard, a meet-up point for household members who are separated, and the specific conditions that mean it is time to go rather than wait. Evacuation orders leave little time for decisions, so the plan exists to be executed, not invented, under pressure.
EvacuationHigh priorityAll US
PSPS (Public Safety Power Shutoff)
A Public Safety Power Shutoff is a deliberate, pre-planned outage in which a utility de-energizes power lines during high wind and extreme fire danger to prevent them from starting wildfires. Shutoffs can last from a few hours to several days and often arrive with little notice, affecting entire towns at once. Households in fire-prone areas should keep fuel, batteries, and a go-bag ready throughout fire season, because a PSPS can arrive with minutes of warning.
PowerHigh priorityCalifornia, Oregon & Nevada fire zones
N+1
N+1 means keeping one more unit of capacity than you actually need to meet your critical load, so a single failure does not leave you without power or water. A household running a 2,000-watt critical load might size its system at 3,000 watts, or keep two smaller power stations instead of one large unit. The same principle applies to water jugs, fuel cans, and medications: the spare is the whole point.
PowerMedium priorityAll US
Atmospheric River
A narrow band of concentrated water vapor that funnels tropical moisture into a long, intense rain event, often lasting a day or more. A single strong atmospheric river can drop a month's worth of rain on California or the Pacific Northwest in a few days, overwhelming creeks, storm drains, and recent burn scars. Households in the West should treat them as a flood and mudslide risk even when they live well inland.
Water & FoodHigh priorityUS West Coast & Pacific Northwest
Emergency Water Storage
Emergency water storage means keeping enough safe drinking water on hand for at least three days — one gallon per person per day, plus extra for pets and sanitation. Store water in food-grade containers away from direct sunlight and heat, rotate it every six months, and never reuse milk jugs or single-use bottles long-term because they leak and grow bacteria. Households in earthquake, hurricane, and wildfire zones where municipal water can be interrupted or contaminated should also keep water purification tablets or a gravity filter as a backup to their stored supply.
Water & FoodCritical priorityAll US
Family Communication Plan
A family communication plan is a written, shared agreement on how your household will contact each other and reunite if separated during a disaster. It designates an out-of-area contact (who is easier to reach when local lines are overloaded), lists every member's phone numbers and medical needs, picks two meeting points (one near home, one outside the neighborhood), and includes a printed copy kept in each go-bag and wallet. Cell networks often fail in the first hours of a major event, so the plan should include text-only and analog fallbacks.
CommunicationCritical priorityAll US
Portable Power Station
A portable power station is a rechargeable lithium-battery unit that supplies silent, emissions-free electricity indoors for phones, laptops, CPAP machines, lights, and small appliances during an outage. It is recharged from a wall outlet, a car, or solar panels, making it ideal for apartments and renters who cannot run a gas generator. Capacity is measured in watt-hours; a 500–1000 Wh unit typically covers a household's overnight phone-and-light needs, while larger 2000+ Wh units can run a refrigerator for several hours.
PowerMedium priorityAll US
Standby Generator
A standby generator is a permanently installed, fuel-powered backup system that starts automatically within seconds of a utility power outage and runs your home's essential circuits. Unlike a portable generator, it is wired into your electrical panel through an automatic transfer switch, runs on natural gas or propane, and sits outside like an air conditioner. Standby generators are most valuable for households in hurricane, ice-storm, and wildfire-PSPS outage corridors who need to keep medical equipment, well pumps, refrigeration, or heating running for days at a stretch.
PowerHigh prioritySevere-weather corridors (TX, FL, LA, Northeast)
Shelter-in-Place
Shelter-in-place means staying safely inside your current location and sealing it against outside hazards rather than evacuating. It is ordered during chemical spills, radioactive releases, severe windstorms, active-shooter situations, and some wildfire smoke events. To shelter-in-place effectively, close and lock all windows and exterior doors, turn off HVAC and fans that draw in outside air, seal gaps with plastic sheeting and duct tape, move to an interior room above ground level, and monitor official alerts via NOAA weather radio or your phone for the all-clear signal.
ShelterHigh priorityAll US
Go-Bag
A go-bag (also called a bug-out bag) is a portable kit of essential supplies packed and ready to grab in seconds when you must evacuate your home on short notice. A complete go-bag contains three days of water and non-perishable food, a first-aid kit, copies of critical documents in a waterproof bag, a flashlight, spare batteries, a multi-tool, weather-appropriate clothing, cash in small bills, and a charged backup battery for your phone. Every member of the household, including pets, should have their own or share a clearly labeled bag stored near the most likely exit.
EvacuationCritical priorityAll US