Because the Grand Canyon region is desert environs, it can be hot. And, the heat can ruin your Grand Canyon experience if you don't take precautions. If you have asthma, diabetes, a heart condition, knee or back problems, or any other health or medical issue, limit both your exertion and your exposure to the heat. The altitude, strenuous climbing, dehydration, and intense inner canyon heat will combine to make any medical problem worse. Stay within your physical limitations, and abilities. Read more on Preventing Heat Illnesses and Tips for staying cool on boiler days.

The heaviest items in your pack should be food and water. The heat, as well as the steep trails this area offers, will sap your energy, and you need to stay well hydrated and well fed. Salty snacks and water or sports drinks should be consumed on any hike lasting longer than 30 minutes. (Remember this mantra: No food = No fuel = No fun.)

Wear good footwear. Many of the trails in the Grand Canyon region are steep, loose and exposed. There is little, or no, margin for error on many of the available hiking trails. As a result, wear sturdy footwear that has good support and provides exceptional traction. Rock falls… <add how to prevent and what to do if a rock fall occurs near you>

If you're exploring when you see lightning, go to low-lying areas away from cliff edges, lone trees, poles, or metal objects. Make sure the area is not subject to flash floods. Do not seek shelter in caves or alcoves.

Become a smaller target by squatting low on the ground. Place hands on knees or back of neck with head between knees. Do not lie down or touch the ground with your hands. Minimize contact with the ground and nearby rocks to minimize ground current effects caused by a nearby strike.

Lightning can strike 10 miles across the canyon, so being below the rim does not make you at a low spot. Finally, rock falls are common following hard rains, so be extra cautious on the trails and exploring the Grand Canyon after a downpour.)

Flash floods are a real possibility when hiking and suddenly a heavy rain starts in the arid Grand Canyon. It is a good idea before you hike to study maps to identify possible escape routes. Be especially careful hiking the Grand Canyon, Marble Canyon, and Glen Canyon regions. The slot canyons in these areas are beautiful, but can be extremely dangerous when it rains. Hikers have been killed in flash floods generated by thunderstorms as far as 25 miles away. Flash floods can occur at any time of the year. Be alert for the possibility of flash flooding anytime that rainfall is forecast. Be especially cautious from July to mid-September when severe thunderstorms can develop rapidly.

Never camp in a dry wash. If you must camp near a wash, camp as high as possible and check for indications of past high water, such as stains on rock walls and debris lines. Be cautious and/or avoid areas subject to flooding - stream beads, narrow canyons, and washes. Be especially cautious in areas posted with flash flood warning signs. Do not cross-flowing water or flooded trails where water is above your knees. Always face upstream when near or in any creek or drainage. Be alert! It does not have to be raining where you are to cause a sudden flash flood in your area. Move to higher ground immediately if you see or hear a flood coming. Do not try to outrun a flood. Warn other people downstream when a flash flood occurs.

Flash floods, which have been described as "more water than you want in less time than you have," are common in Northern Arizona. This is because the arid, sparsely vegetated environments found in this area have little capacity to absorb rainfall. The resulting runoff moves rapidly through the narrow canyons and steep terrain found throughout Northern Arizona. In many areas, even small storms can turn normally dry streambeds into raging torrents of water in a matter of minutes.

A flash flood can travel miles beyond the rainfall that generated it, catching unwary hikers and motorists by surprise. In Lower Antelope Canyon on August 12, 1997, twelve hikers were caught in a flash flood that filled the narrow canyon with water up to 50 feet deep. The hikers did not recognize the flood danger until it was too late, probably because the storm that caused the flood occurred miles away. Only one hiker survived! > Read More on Flash Floods