Poisonous Reptiles. The park contains copperhead snakes and four species of rattlesnakes, although these are seldom seen in daylight. Though poisonous, they are protected in the park. Do not molest or harm them. Very few snakebites occur in the park. Most of these involve bites to the hands of people who have reached into places where they couldn’t see a snake resting or hiding. The general precautions are these: Stay on trails after dark and use a flashlight, and avoid bushes and damp areas. There are no poisonous lizards at Big Bend, but if you molest lizards they may bite you. Tarantulas and Scorpions. Tarantulas, contrary to horror films, will not bite you unless you annoy them. And the park species of scorpion is not deadly, although if you are stung, get prompt attention. No Medical Services. There are no doctors or nurses in the park. The closest hospital, in Alpine, is 174 kilometers (108 miles) from park headquarters. Terlingua Medics, a nonprofit first-aid station and medical care facility, is located 42 kilometers (26 miles) west of park headquarters, in Study Butte. The trained paramedics can provide interim care until further help can be obtained in Alpine. Carry your own first-aid supplies (including tweezers). Please notify the nearest park ranger or park headquarters immediately of accidents or emergencies. Use Water Wisely. Carry drinking water with you whenever you are in desert country. This is particularly a must when hiking: 4 liters (1 gallon) per day per person is a good rule of thumb. And remember: Start your return trip _before_ half of your water supply is used up. Floaters and boaters, do not drink the river water: Carry your own. Any spring water used for drinking should be treated first. Flash Floods. High water is a threat during the flash floods that may follow summer thunderstorms. You must be alert for this because a flash flood may travel down the watershed to you even though you were not rained on. Flash floods make roadway dips potential death traps. If you are caught in high water, drive slowly to avoid stalling your engine: Do not splash through at a high speed. And by all means, avoid any high water! Washouts are a hazard in a storm and afterwards, so be on the lookout for them. These same precautions about high water and low spots apply to camping, too. Do not camp in washes and arroyos. They could turn into swirling rivers while you sleep, and you might not even have the warning of raindrops to wake you. Park Regulations Driving.