What to Do Right Now After a Nuclear Blast

Move to the nearest solid building. Concrete or brick structures offer the best protection. Basements are ideal. Avoid vehicles — they offer minimal radiation shielding.

Do NOT look at the flash. It can cause permanent blindness even at great distances.

Remain inside for at least 24 hours unless instructed otherwise by emergency services. The most dangerous fallout settles within the first few hours. Close all windows and doors. Turn off ventilation systems that draw air from outside.

Do NOT go outside to look for family members. You cannot help others if you are exposed to lethal radiation.

If you were outside during the blast, remove outer clothing and shoes before entering shelter. Place contaminated clothing in a sealed plastic bag. Shower or wash exposed skin with soap and water. Do not use conditioner — it binds radioactive particles to hair.

Listen to battery-powered or hand-crank radio for official instructions. Do not rely on cell phones — networks will likely be down. Follow instructions from emergency management authorities about when it is safe to leave shelter.