…stand directly behind your door, but do not open the door, even if the radiation knocks.
“If there is a significant radiation threat, health care authorities may or may not advise you to take potassium iodide. Potassium iodide is the same stuff added to your table salt to make it iodized. It may or may not protect your thyroid gland, which is particularly vulnerable, from radioactive iodine exposure.”. This page may or may not interest you.