Emergency managers talk about the first 72 hours because that is often how long it can take for help to reach every neighborhood after a widespread disaster. Roads may be blocked, and grocery stores, pharmacies, and gas stations may be closed or unable to take cards if the power is out. Seventy-two hours is a minimum. The American Red Cross recommends a 3-day supply in a bag you can take if you evacuate, and about two weeks of water and food at home.
Six needs, plus water and food
| Need | What it means in practice |
|---|---|
| Information | A way to hear official updates if the phone network, internet, or power is down — typically a battery or hand-crank radio that can receive NOAA Weather Radio. |
| Power | A way to keep phones and essential devices on: charged power banks with a known watt-hour capacity, spare batteries, and, if you have one, a generator used only outdoors. See runtime examples. |
| Light | A flashlight or headlamp for each person, plus spare batteries. Headlamps leave both hands free. Electric lights are safer than candles. |
| Medical | A first-aid kit you actually know how to use, plus several days (ideally a week) of prescription medicines, spare glasses, and device batteries. |
| Climate | A way to stay cooler without air conditioning in the summer heat of the Lowcountry, and warm enough if a winter outage knocks out the heat. |
| Protection | Work gloves, a whistle, rain gear, sturdy shoes, and simple respiratory protection for dusty or moldy cleanup. Plastic sheeting and duct tape if you are told to shelter in place. |
Water, food, sanitation, documents, cash, and pets sit beside those six needs. They are the items that run out first.
At home versus in a bag
Keep a home stock in a cool, dry place everyone knows. Store water next to it. The home stock is for sheltering in place.
Keep a go-bag (one bag per adult who can carry one, and a smaller bag or identified items for children) packed and close to an exit. The bag is for when you are told to leave, or when you choose to leave early. See Evacuation and go-bag.
If you also spend time at work or in the car, a smaller 24-hour kit there covers the chance that you are not at home when something starts.
Planning quantities for your household of 4 people
These figures use official U.S. planning rules: 1 gallon of water per person per day, and at least several days of food. In extreme heat, water needs can rise, so treat the gallon as a floor.
Three days
- Water: 12 gallons for 4 people, plus pet water.
- Food: the meals and snacks your household will actually eat for three days with no cooking, or with only a safe outdoor method. Include a manual can opener. As a planning check, use 2,000 calories per person per day (the general figure on U.S. food labels): about 24,000 calories for 4 people over 3 days. Needs vary by age and activity; see the USDA ranges.
- Medicines: at least three days, and a week if prescriptions allow (Red Cross).
- Light: one flashlight or headlamp per person (4 in all), spare batteries.
- Power: charged power banks and cables that fit every phone in the house. Capacity and runtime examples are on the power page. A common starting point is on the order of 20,000 mAh (about 74 Wh at 3.7 V) per person who relies on a phone, not one bank for the whole house.
- Information: NOAA weather radio, plus important numbers on paper.
Two-week supply
Build this after the three-day layer is in place. A printable tick list is on the supply checklist.
- Water: 56 gallons for 4 people — a mix of store-bought bottles and food-grade containers.
- Food: 14 days of familiar, shelf-stable meals. At the 2,000-calorie planning figure, that is about 112,000 calories for 4 people. Check against the USDA ranges by age and activity if your household differs.
- Hygiene and sanitation supplies for the same period, including bags, wipes, and unscented bleach (used only as the EPA or CDC surface directions specify).
- Fuel for any generator, stored legally and safely, with a realistic run-time plan — fuel often runs out before the outage does.
What “ready” looks like on an ordinary week
- Everyone at home can point to the supplies and the bags.
- Phones are signed up for county alerts, and a NOAA radio is programmed and tested.
- You know your evacuation zone by address and have a paper map and a meeting place.
- Prescriptions are not left on a “we will refill tomorrow” margin.
- You have walked through the family plan once, including how to shut off utilities only if officials tell you to or if you know it is safe.
A kit you never practice with is only a box. Checking expiration dates twice a year — a common cue is when you change smoke-alarm batteries — keeps the plan honest.