To remain comfortable and safe, respect certain rules of the desert. Drink 2 quarts of water a day in winter and 1 quart per hour in summer. Keep a jerrican (which holds 5 gallons) of water in your car, plus extra bottles. Water fountains along the way don't always work. Flash floods pose an occasional danger from September through March, especially after rainfall farther north. If even a small amount of water is flowing across the road, wait for it to stop (it can take a while); it can be a sign of imminent flooding. Driving at night isn’t recommended; plan to reach your destination by 5 pm in winter and by 8 pm in summer. Make sure to have a car charger for your cell phone; service is spotty, and phones seeking available networks eat up battery life.