"Bug-out" bags are kits made up with essential items so that you can evacuate at a moment's notice, without having to go tearing through the house, trying to find everything you'd need. It's advisable in likely target areas with large populations, that would be extremely difficult to evacuate in a timely manner.
May want to get some of this , Potassium Iodide, it's too cheap not to have some on hand. They're legit, it's where I got mine.