"We recommend 72 hours worth of supplies, because it may take that long before officials can get to your area," says Kelly Huston of the California Emergency Management Agency. That means three days worth of food and water, which equals one gallon per person, per day. FEMA recommends this large amount of water for evacuations via car or if you're in a shelter as opposed to pedestrian evacuations, when you should only take as much as you can easily carry. Food-wise, Huston recommends cereal bars, nuts, crackers -- "basically anything that can last a long time and is non-perishable and ready to eat." Ward adds, "If you have canned food, bring a can opener but don't bring anything that requires mixing or heating." Also, because water has an expiration date (which has to do with the plastic it's bottled in), "Make sure it has a few years of shelf life when you put it in your bag," advises Huston.