Threat timeline and priorities

The page above sets the order everything else in this app follows. This is what the order assumes, and the two places a real household should depart from it.

What the rule of threes is actually for

It is a mnemonic for ranking, not a set of timings. Three minutes, three hours, three days, three weeks is memorable precisely because it is round, and every one of those numbers moves a long way with circumstances.

• Three hours without shelter is a temperate estimate for a dry adult in bad weather. In cold water it is wrong by an order of magnitude: the gasp response arrives in seconds and useful grip and swimming ability go within minutes.
• Three days without water shortens sharply with heat, exertion, fever, vomiting or diarrhoea. It lengthens at rest in the cold.
• Three weeks without food varies enormously with body composition and is not a target anyone should plan toward.

None of that makes the mnemonic wrong. It is doing one job well: telling you that a fortnight of tinned food is worth less than a fortnight of water, and that both are worth less than a way to stay warm and dry. Keep it for the ranking. Do not use it as a clock.

What actually kills people here

This is the part the mnemonic cannot tell you, because it was built for exposure in the open, and it ranks threats by how a person dies alone outdoors.

A British household emergency does not kill people that way. Nobody in a UK power cut dies of thirst on day three. The pattern is different and it is well documented:

• Cold, acting on existing illness. England and Wales record substantial excess deaths every winter, concentrated in older people, where cold indoor temperatures worsen cardiovascular and respiratory conditions. This is the single largest cause and it is slow, quiet and easy to underestimate.
• Carbon monoxide, from a stove, barbecue, generator or heater brought indoors by somebody who was cold. It cannot be smelled and it kills people while they sleep. Every winter it kills adults who believed they were being careful.
• Falls and fire, from candles, dark stairs, and unfamiliar improvised arrangements.
• Interrupted treatment. The person who was already ill, whose medicine ran out, whose oxygen concentrator needed mains power, or whose dialysis or clinic appointment did not happen.

Where your order differs from the standard one

The parent page buys in the order water, heat and shelter, food, energy, medical, comms. That is the right default for a household of healthy adults. Two things move medical up it, and you should decide now whether either applies to you.

Medicine with a short safe interruption. Some treatments cannot be paused for a fortnight while you work through the rest of the list.

If any row applies in your house, medical is first, ahead of water. Not because it is more important in the abstract, but because water can be improvised in a week and an insulin supply cannot.

And information is not last. The parent page puts comms sixth, which is right if comms means talking to relatives. It is wrong if comms means finding out whether the water is safe to drink, whether to leave, and where the rest centre is. A wind-up radio is a cheap item that belongs much earlier than sixth, because it is what tells you which of the other five you are about to need.

Knowing which phase you are in

The phase model is the most useful thing on the parent page and it gives no way to tell where you are. These are the observable triggers, and they are worth agreeing as a household in advance so that nobody has to argue about it on the day.

The most useful line in that table is the Phase 2 one about your own stores. It is measurable inside your house, on a shelf you can look at, and it does not depend on believing anything you are told.

The trap in the phase model

The phases describe a slide, and slides are hard to notice from inside. The parent page is explicit that shortages worsen over weeks and months rather than overnight, and that is exactly what makes the model difficult to apply: there is no moment that announces itself.

So set the trigger now, while it costs nothing. Write down what would have to be true for your household to start rationing, and what would have to be true to stop waiting for services to come back. A number decided in advance is a decision. The same number decided while frightened is a rationalisation.

And note that every phase is reversible. Nothing in this app assumes a one way trip. Most disruptions resolve, most of the time, and a household that has moved to Phase 2 and then goes back to normal has lost nothing except some stored food it was going to eat anyway.