A heat wave that broiled the southwestern United States is finally cooling (to 100-plus degree days in some places, but still.) Tropical Storm Cindy has caused tornadoes and flooding all the way into Ohio. They have something in common: both these types of natural disasters require lots of stored water. At least five people died in the southwest from heat-related illnesses. In Phoenix, a radio station and PetSmart store handed out protective booties for dogs’ paws. The U.S. Border Patrol is transferring agents with search and rescue training to answer emergency calls from people trying to cross the border through the desert. People can’t carry enough water for the trip, which can be more than a week long. Enough water can both treat and help reduce the risk of heat-related illnesses. During a heat wave, you should drink at least a gallon of water per day if you’re outside, suggests Weather.com. Drink even when you’re not thirsty, suggests Ready.gov. Also, add sports drink powder to your food storage. Sports drinks can help replace electrolytes you sweat away. Electrolyte loss can cause heat cramps. Don’t drink sodas or other sugary or caffeinated drinks or alcohol. Those drinks will make you more dehydrated, not less. If possible, drink cool drinks, because they’ll help you cool down. But don’t drink them really cold, because that can cause stomach cramps, suggests the U.S. Centers for Disease Control and Prevention. When you hike in hot weather, drink plenty of water before you go. Even on a leisurely hike, you should drink at least a quart every two hours. If all else fails and you’re stuck in the desert with little water, follow these tips from Business Insider. People who face flooding like that from Tropical Storm Cindy would seem to have the opposite problem of too much water. But flood water is a hazardous gumbo of untreated sewage, debris, chemicals, dead animals, and waste from overflowing drains. About 1,000 evacuees of Hurricane Katrina in Texas and Mississippi came down with diarrhea and vomiting, according to the CDC. To prepare for Cindy, the Federal Emergency Management Agency sent 200,000 bottles of water to Louisiana. After a flood, you need clean water for drinking and sanitation. Ready.gov recommends you store at least a gallon of water per person per day for three days. Nursing mothers, children, and people with special health care needs might need more. The site also recommends you buy bottled water rather than prepare your own, because commercially bottled water lasts longer. If you bottle your own, buy food-grade water storage containers, follow directions for bottling it at Ready.gov, and replace self-bottled water every six months. Keep additional bleach and hand sanitizer around too. The CDC recommends you use hand sanitizer every time you contact flood water. Also sanitize any object that has touched flood water. That’s where bleach is your friend. One cup per five gallons of water is sufficient to sanitize most things like undamaged food and water containers, toys and nonporous surfaces. Bottle nipples and pacifiers and porous items like wood should be thrown out along with any food that may have been contaminated. Whether an emergency is human-caused or natural, no matter how small or large it is, you’ll need water. If you don’t have emergency water, get some before you buy any more emergency food. After all, the average person can last about three weeks without food, but only a few days without water. Melissa Rivera is a jack-of-all-trades who is master of none. She has been a writer and editor for more than 15 years.