Grand Canyon National Park
The National Park Service seems to believe that park visitors can never hear too much about smart hiking, the dangers of heat, and the importance of water. The message turns up on park publications, at trailheads, and on bulletin boards in and around the park. Despite the ubiquitous message, many hikers still require medical attention in the canyon. Some mistakes are common even among relatively knowledgeable hikers. One is to not eat enough during strenuous hikes; eating is just as important as drinking. Another is to let a surge of adrenaline carry you too far into the canyon during the easy hike down. Temperatures climb steadily as you descend, and the hike out can take twice as long. Another is not wearing adequate sun protection. Without sunscreen, a hat, and light-colored clothing on your skin, the heat can drain you even during the cooler months. So be careful. Also, remember that the park's wilderness trails are far more rugged than its corridor trails. If you lack route-finding skills, can't read a topographical map, or are not fit, stay off these trails.
Spring and fall are the best times for canyon hiking. During summer, temperatures in the inner canyon can easily top 110 degreeshot enough to be dangerous even for the well prepared. The rim trails, being much cooler, are better choices than the canyon trails during hot weather. In winter, the North Rim closes. On the South Rim, most trails drop into the canyon through north-facing cliffs, so they can be icy or snow-covered even when the rim itself is dry. In addition to being cooler, all the trails are less crowded during non-summer months. Even so, you probably won't find much solitude on the corridor trails. These trails, which can be unbearably crowded in summer, nearly always have a few peoplenot to mention mulesupon them.
Details mentioned in this article were accurate at the time of publication