Inside my backpack I have:
Life Straw, Large Loksak with tubing plus Water Purifier Tablets (Katadyn), AM/FM Radio (Extra Batteries), Extra Socks, Jacket, Hat & Gloves, Sit Pad, Large Mylar Blanket, Sunscreen, Insect Repellent, Amp-3 PPK, Amp-3 EDC, Snacks, Stay Alert Gum, Hoo-Ahhs (For keeping clean), Emergency Food, and Hygiene Products.
Remember: More people will die from poor hygiene then anything else. Stay clean and hopefully, stay alive.
If your going out of the house this bag needs to go with you or what good is it doing at home! I have to remind myself of this one... Extra walking shoes in your car maybe in the wheel well if you have extra room.