WW3 WW3 PREP / FIELD LIBRARY
Radiation emergencies: official family guidance
Know where official instructions come from before an emergency.
Follow radiation-specific official instructions
CDC preparedness guidance emphasises getting inside, staying inside and staying informed. The actual incident and local instructions determine what to do next. This page is a preparation guide; it does not assess a building or issue a live shelter or evacuation decision.
Keep the household plan accessible
Know official information channels, prepare a radio and keep contact and care information on paper. Discuss children, pets and essential equipment. Use the linked official guidance for incident-specific measures rather than assuming any mask, filter or kit protects against all radiation.
Do not treat iodine as universal protection
Potassium iodide has a limited role against radioactive iodine affecting the thyroid; it does not protect the whole body or all radiation types. Do not take it unless instructed by emergency/public-health authorities or a healthcare professional. Do not leave shelter to search for it during an incident.
Primary source
Official guidance / Orientações oficiaisRead the full instructions and your local official guidance. References accessed 3 October 2026. No independent expert review.