Hiking in the Grand Canyon during the summer months presents unique hazards, the result of extreme heat and some of the steepest and most rugged terrain on earth. Every year, scores of unprepared hikers that were initially lured by what seemed like an easy downhill hike, experience severe illness, injury and death from hiking in the Grand Canyon.

For both public and employee safety, the National Park Service urges SPECIAL CAUTION for all hikers during the summer months. Below are tips on how to hike smart in the Grand Canyon.

Hiking Smart in the Grand Canyon

For your safety, avoid hiking in the hottest part of the day. When inner Grand Canyon temperatures are extremely high, access to inner Grand Canyon trails may be restricted to early morning and evening. Information on trail restrictions and trail closures is available at (928) 638-7888 (press 1-3-1).

Rangers respond to heat exhausted hikers every day during the summer – don't become one of them!

Be aware that efforts to assist you may be delayed during the summer months due to limited staff, the number of rescue calls, employee safety requirements and limited helicopter flying capability during periods of extreme heat. 

Do not rely on physical strength alone; hiking smart will take you much farther. Use the information below to hike smart.

10 Grand Canyon Hiking Essentials

1. Water – plain and some with electrolyte replacement.

2. Food – especially salty foods. Eat twice as much as normal.

3. First Aid Kit – Band-Aids, ace wrap, antiseptic, moleskin, etc.

4. Map – while many trails are well marked, maps are helpful tools.

5. Pack – to carry the essentials.

6. Flashlight/Spare Batteries – allows you to hike out during the cool of the evening.

7. Spray Bottle – fill with water for your own personal air-conditioning system.

8. Hat/Sunscreen – to keep the sun off you and protect your skin.

9. Whistle and/or Signal Mirror – for emergency use.

10. Waterproof Clothing – poncho or jacket; especially useful during monsoon season (mid-July to early September).

Tips for Safe Hiking

1. Drink and Eat Often – You Need It

You sweat around one-half to one quart of fluid for every hour you walk in the heat.

This fluid/electrolyte loss can exceed two quarts per hour if you hike uphill in direct sunlight and during the hottest time of the day. Because inner Grand Canyon air is so dry and hot, sweat evaporates instantly, making its loss almost imperceptible. Keep an eye out for salt rings on your clothes.

Do not wait until you are feeling thirsty to start replacing fluids and electrolytes. By the time you feel thirsty, you are already dehydrated. Even a mild level of dehydration can make hiking a lot less fun. The more dehydrated you become, the less efficient your body is at cooling making hiking more difficult.

Your body can only absorb about one quart of fluid per hour, so drink one-half to one quart of fluid every hour that you are hiking in the heat. Carry a water bottle in your hand and drink small amounts often. Alternate between water and a sports drink with electrolytes.

Balance your food intake with fluid consumption, or else you run the risk of becoming dangerously debilitated and severely ill. Food is your body's primary source of fuel and salts (electrolytes) while hiking in the Grand Canyon. Eat a salty snack every time you take a drink.

2. Wait for the Shade - Avoid Hiking Between 10am and 4pm!

Even if you are eating and drinking correctly you still need to avoid hiking in direct sunlight during the hottest part of the day. Sun temperatures are 15 to 20 degrees Fahrenheit (9C-11C) hotter than posted shade temperatures. And keep in mind, the farther into the canyon you go, the hotter it gets!

Plan your day so you are not hiking between the hours of 10 a.m. and 4 p.m. Take a break near shade and water to avoid the worst heat of day. Enjoy a predawn start and a late afternoon finish. Experienced desert hikers know that the timing of their hike is the most important factor in avoiding hazards. Most of the people who need emergency medical help in the Grand Canyon due to heat illness are hiking between 10 a.m. and 4 p.m.

Always bring a lightweight flashlight to give yourself the option of hiking out after dark in the event that illness, injury, or enjoyment should slow you down.

3. Stay Wet and Stay Cool – Soak Yourself with Water

This is one of the best things that you can do for yourself; it will help decrease your core body temperature. Whenever you are near water, make sure that you wet (actually soak) yourself down. If you hike while soaking wet you will stay reasonably cool. This will make a wonderful difference in how well you feel, especially at the end of the day!

4. Watch out for Health Hazards – Know the 4 H’s

While many hikers have experience in the mountains, the inner Grand Canyon is a desert. The hot, dry environment and the hiker’s exertion combine to complicate the effects of fatigue. During the summer season when inner Grand Canyon temperatures routinely exceed 100F (40C), dehydration is common and can lead to heat exhaustion.

More serious illnesses associated with desert hiking are heat exhaustion, hyponatremia, heatstroke and hypothermia, known as the hazardous H’s. The following are symptoms and ways to treat these conditions:

    Heat Exhaustion is the result of dehydration due to intense sweating. Hikers can lose one or two quarts (liters) of water per hour. Rangers at Phantom Ranch and Indian Garden treat many cases of heat exhaustion each day in summer.

        Symptoms: pale face, nausea, vomiting, cool and moist skin, headache, cramps.

        Treatment: drink water with electrolytes, eat high-energy foods (with fats and sugars), rest in the shade for 30-45 minutes, and cool the body by getting wet.

    Heatstroke is a life-threatening emergency where the body's heat regulating mechanisms become overwhelmed by a combination of internal heat production and environmental demands. Your body loses its ability to cool itself. Grand Canyon has two to three cases of heatstroke a year. Untreated heat exhaustion can lead to heatstroke.

        Symptoms: flushed face, dry skin, weak and rapid pulse, high core body temperature, confusion, poor judgment or inability to cope, unconsciousness, seizures.

        Treatment: the heatstroke victim must be cooled immediately! Continuously pour water on the victim's head and torso, fan to create an evaporative cooling effect. Immerse the victim in cold water if possible. Move the victim to shade and remove excess clothing. The victim needs evacuation to a hospital. Someone should go for help while attempts to cool the victim continue.

    Hyponatremia (water intoxication) is an illness that mimics the early symptoms of heat exhaustion. It is the result of low sodium in the blood caused by drinking too much water and losing too much salt through sweating.

        Symptoms: nausea, vomiting, altered mental states, confusion, and frequent urination. The victim may appear intoxicated. In extreme cases seizures may occur.

        Treatment: have the victim eat salty foods, slowly drink sports drinks with electrolytes, and rest in the shade. If mental alertness decreases, seek immediate help!

    Hypothermia is a life-threatening emergency where the body cannot keep itself warm, due to exhaustion and exposure to cold, wet, windy weather. Avoid hypothermia by checking at the Grand Canyon View Information Plaza or the Backcountry Information Center for the latest weather and trail conditions, taking layered clothing for protection against cold and wet weather, eating frequently, replacing fluids and electrolytes by drinking before feeling thirsty, and avoiding exposure to wet weather.

        Symptoms: uncontrolled shivering, poor muscle control, careless attitude. Look for signs of the ""umbles"" - stumbling, mumbling, fumbling, grumbling.

        Treatment: remove wet clothing and put on dry clothing, drink warm sugary liquids, warm victim by body contact with another person, protect from wind, rain, and cold.

(Updated by the Arizona Office of Tourism - 2009)