Minutes to hours after a nuclear blast are critical for survival. Disaster experts explain how to protect yourself in a worst-case scenario.

• Survivors of a nuclear attack would have about 15 minutes before sand-like radioactive particles, known as nuclear fallout, reached the ground.
• People should look for shelter in the opposite direction of fallen buildings.
• The best shelters are buildings like schools or offices with few to no windows and a basement for camping out. If there aren't sturdy buildings nearby, it's still better to be indoors than outside.
• If you take cover in a multistory building, choose a central location and steer clear of the top and bottom floors. If the building has windows, stand in the center of a room.

The hours after a blast are critical for reducing radiation exposure.

• People who were outside during an explosion should shower as soon as possible, making sure the water is warm and soap is applied gently. Scrubbing too hard could break your skin, which acts as a natural protective barrier. You should also cover any cuts or abrasions while rinsing off. 
• Don't use conditioner, body lotion, or face cream after exposure to a nuclear blast, since these products can bind to radioactive particles and trap them in your skin and hair.
• Blow your nose and wipe your ears and eyelids, since debris could get stuck in these places.