Ordinary Readiness

An old backpack or duffel is fine. A backpack leaves your hands free and so is preferable. Bags sold as emergency kits cost more and typically come filled with things you don't need. If you need to buy one, a simple school backpack like the JanSport SuperBreak Plus works well. A packed bag weighs 10 to 15 pounds, about what a kid carries to school. If you might have to walk a few miles with it, the Osprey Daylite Plus adds a chest strap and a waist belt, which is what keeps a loaded pack steady.

For a go bag, plan on a minimum of half a gallon (about two liters) per person per day. One day of sealed bottled water and a way to treat more is typically the right practical balance to have in a backpack. If the bag lives in the car, a case of bottled water from Costco is a very easy approach. The Katadyn tablets keep for years.

Three days is about 6,000 calories per person. One box of 15 Clif bars and one box of 12 granola bar pouches gets there, for about $23 a person. Nut butter packets, crackers and dried fruit fill in, and the granola pouches from the home list only need cold water. Bars carry a best-by date about a year out, so check the dates once a year, when you swap the kids' clothes.

One full change with long pants and a long-sleeved shirt, extra socks and underwear, a sweatshirt, and a rain shell. Then what you would take for an overnight trip: a toothbrush, soap, contact lens supplies, period products, and an old pair of glasses. Swap kids' clothes once a year at the start of school.

The kit is for cuts and scrapes; add a few days of your own fever and pain medicine. The masks are for wildfire smoke. Pack the headband masks from the home list, not the ear-loop ones: the EPA's smoke guidance says masks with ear loops don't seal well enough. No respirator approved in the US is made in a child's size. A small KN95 is better than nothing for a child, but the plan for kids is to get them out of the smoke.

The things you need to see at night and recharge your phone.

A blanket is easy to throw in the top of a backpack.

A deck of cards, a coloring book, a small stuffed animal that can live in the bag. Add a copy of the contact card from the family plan. For a baby, pack three days of diapers, wipes and ready-to-feed formula (the kind that doesn't need water added). Update the sizes when you swap the clothes.

Most public shelters don't take pets, so decide ahead of time where you would go with yours. Pet-friendly shelters and boarding kennels commonly ask for proof of vaccination, and some hotels do. Add the microchip number, any medication, and a photo of you with your pet in case you get separated.

In this order: a week of prescriptions and any medical devices, glasses and hearing aids, wallets and keys, phones and chargers, the laptop, the documents folder, the weather radio from the home list, the pets, the kids' comfort items. Write it for your house, print it, and tape it where the bags are.

Card readers and ATMs stop working when the power is out. Add a spare car key and house key. The folder is the paper set from the documents list, in a waterproof pouch. It holds copies, so waterproof is enough; bags sold as fireproof are not rated to survive a house fire.

The two places that work are by the door to the garage and in the trunk of the car. In the trunk, the bag also covers most of the getting-home group on the car list. A trunk gets hot, which is hard on food and medicine, so check those twice a year if the bag lives there. Keep the car at half a tank or better, and know two ways out of your neighborhood.