Hours 24 to 72: the first 72 hours
Goal: hold out without outside help. 72 hours is the preparedness standard because, after a major disaster, emergency services can't reach everyone right away: FEMA warns of this in its public training, and the Red Cross asks for 3 days of water and food to evacuate and 2 weeks for the home. Ready.gov no longer sets an exact number: it talks about having supplies for "several days." Think of 72 hours as the minimum, not the goal.
- Keep up the shifts. No one should go more than 16 to 18 hours without sleep; exhaustion causes the serious mistakes (cuts, falls, poisonings).
- Daily hygiene: hands with soap and water or gel before eating and after the bathroom; trash in closed bags away from where people sleep (chapter 21).
- Check the health of each person and each pet twice a day: dark urine, dizziness, confusion (dehydration or heat), chills (cold), wounds that turn red.
- Medicines: keep track of each person's remaining doses in the log.
- If the tap water is in doubt, don't drink it untreated: boil it or disinfect it with bleach (chapter 3). Follow the notices from your water utility.
- Organize with your neighbors: who has what, who needs help, what time you meet (chapter 9).
- Prepare the next decision: if conditions get worse, where would you go and by what route? Keep the backpacks ready by the door.
Consumption rules for this phase
| Resource | Rule |
|---|---|
| Water | By hour 72 you'll have used about 3 gal (11.4 L) per person, plus your pets' water. Ready.gov: don't ration drinking water unless authorities order it; drink what you need today and look for more for tomorrow. Save on hygiene: wash dishes with little water, use disposable plates, wipes. |
| Power | Recharge phones from the power station or power bank, one at a time, only up to 80–90%. Use the car charger only with the car outdoors, never in a closed garage. |
| Food | Check what's left in the freezer with a thermometer; if it was at 40 °F (4 °C) or higher for more than 2 hours, throw it out (chapter 9). Move on to the pantry. |
| Communications | News every 3 hours on the hour; FRS radios on the hour, 5 minutes. |
How much each power source gives you
There's no single figure: it depends on your equipment's capacity and what you plug in. Calculate it with this formula and write the result on the equipment's label:
Hours of use ≈ (capacity in Wh × 0.85) ÷ appliance consumption in W. The 0.85 accounts for conversion losses; it's a conservative approximation. The capacity in Wh is on the power station's label; the consumption in W is on the appliance's label or manual.
| Example (assumption) | Calculation | Approximate result |
|---|---|---|
| 500 Wh station with a 10 W fan | 500 × 0.85 ÷ 10 | ~42 hours |
| 500 Wh station with a 25 W fan | 500 × 0.85 ÷ 25 | ~17 hours |
| 500 Wh station, phone charging (assume 15–20 Wh per full charge) | 425 ÷ 15 to 425 ÷ 20 | ~21 to 28 charges |
| 10,000 mAh power bank | Losses reduce its usable capacity | About 2 charges of a typical phone |
Power priority (if there isn't enough for everything): 1) electrical medical equipment, if anyone uses it; 2) alerts and news radio; 3) one task light; 4) on-call phone; 5) fan for whoever needs it most (heat); 6) everything else. Flashlights and battery radio: keep track of the sets of batteries used in the log.
