GRAND CANYON NATIONAL PARK, Ariz. -- If anyone tells you to go take a hike, try the Grand Canyon.
"It's one of the things you check off in life -- a life experience," said Mike Meyer, a National Park Service supervising ranger on the canyon's south rim. "You hike the canyon." This is a perfect time for it. In spring and fall the weather is cool and hiking conditions are more favorable than in summer, when it's hot and crowded.
"This is a desert," exclaimed Beverly Perry, a back country park ranger specialist. "People don't come to Phoenix for a summer vacation." But they do come to the canyon, despite the scorching heat.
About 4 million visitors come to the Grand Canyon each year. Most of them view the canyon from the south rim and retire for an ice cream cone or a cool drink. But more than a
million of them insist on a more intimate view by hiking into the canyon for a day or longer, which is a bit like mountain-climbing in reverse. First you go down a mile into the canyon, then you trek back up.
"You have to be a reasonably healthy and fit person to hike here," Ms. Perry warned. "One of the most common problems we have is heat exhaustion."
Of all the national parks, the Grand Canyon provides medical assistance to the greatest number of visitors -- 317 cases last year and probably more than 400 this year.
A recent nine-mile hike up the Bright Angel Trail -- the canyon's most popular -- from the Colorado River at the bottom of the canyon demonstrated the joys and perils of hiking the Grand Canyon in the summer. It took nine hours.
The temperature was 96 degrees and the sky a cloudless cobalt blue. The weather seemed a blessing because the canyon's red and buff colors stood out brilliantly in the bright sunlight. But it felt like a furnace whenever the trail was exposed to direct sunshine.
"Take your time and drink lots of water," advised Dave Doarn, a park ranger at the bottom of the canyon. On a trip like this, it's not unusual for a hiker to down 4 quarts or more to replace fluids lost through perspiration.
On the other hand, the views were spectacular, and it did not take long to learn that the Bright Angel Trail actually is an international highway, of sorts. A "hello" to approaching hikers often is answered in a foreign accent. About 40 percent of the park visitors are foreigners.
Karen Van Vlaenderen of Flanders in Belgium said: "We have no mountains. We are not used to this. Belgium is flat."
Jan Svensson of Goteborg, Sweden, said his country has mountains but nothing like this, adding: "It's hard, it's hot."
David Oliver of Eyemouth, Scotland, often hikes the Scottish highlands. Of the Grand Canyon, he said: "The heat is killing us."
Repeatedly, visitors declare it one of a kind.
After hours of trudging, the canyon rim still seems impossibly far. Most hikers carry a backpack, and the routine becomes: Walk, stop, rest and walk again.
Thoughts are focused on advancing up the trail, a stretch at a time. Such concentration offers a kind of solitude. Even under physical stress, the changing colors of the canyon as the sun crosses the sky are captivating -- but best viewed during the rest stops to avoid stumbling and falling off the narrow trail and hundreds of feet down the sheer walls.
"This trail is a heartbreaker," said Ron Harris of Phoenix. "It gets worse at the top, just when you have no energy left." He passed the time reciting poems on fly-fishing and wily mountain trout.
Reaching the top of the canyon is pure joy, a personal triumph that is not marred by feeling totally spent, soaked in sweat and shivering in the cool wind as the sun sets. Occasionally, a hiker who has ignored all the warnings about eating and drinking properly suffers the classic symptoms of dehydration: Fatigue, headache, nausea and vomiting.
"We have a saying," said Ranger Perry. "Fatigue is not an emergency."
A ranger is likely to offer food and water and even an overnight rest in the canyon before the hiker is invited to continue. Or the hiker, after recovering, might be given a flashlight to finish in the cool of the night.
Only if a hiker is injured and can't walk is he or she likely to be evacuated, sometimes by mule but usually by helicopter, which costs about $250.
Even hardened marathon runners comment on how hard a Grand Canyon hike can be because of the heat and the elevation, 6,860 feet atthe south rim.
"People who have the most trouble are those who try to hike to the Colorado River and back in one day," said Ms. Perry. "It seems easy going downhill. They don't know what a problem they have until they start uphill."
Public attitudes contribute to the problem.
"There is a sense by people that they are not responsible for themselves, and somebody will bail them out," Ms. Perry said. "They don't realize things can go wrong quickly. The concept of self-rescue is an old one -- particularly in the mountaineering community. But it is almost unheard-of in recreation."
As a result, the Grand Canyon enforces a sense of self-reliance that often draws people to wilderness hiking.
Said Ms. Perry: "People fall in love with it, or it's the worse thing they've ever done and they won't come back."