Planning
Define duration, people, measurement intervals, weather limits and immediate stop signs. Bring water, light, communications and first aid; keep both exits clear. Begin in daylight without additional earthwork or fire.
Emergency preparedness · 18 min
Test the temporary room only briefly at first, in suitable weather and with an exit available at all times. The aim is not endurance but checking air, moisture, temperature, communications, routes and psychological strain.
Decision compass
Four questions lead from observation to a clear, safer action.
What needs to be clarified now?
Remember: Observe → assess → choose a safer option → act.

A short supervised test reveals limits and prevents false confidence.
Define duration, people, measurement intervals, weather limits and immediate stop signs. Bring water, light, communications and first aid; keep both exits clear. Begin in daylight without additional earthwork or fire.
Record CO₂, temperature, humidity, odour, sounds, water and movement. An outside contact confirms start and finish. Symptoms or structural concerns end the drill immediately.
After the drill, ventilate, dry, inspect and secure the structure. Resolve loose soil, water, decay or movement professionally. Do not leave a temporary structure in use as an assumed permanent shelter.
Decision training
Correct: B. Photographs, plans, specialist checks and a functional test show whether the proposed solution works safely at the actual site.