Frying an egg in the Arizona heat


How to Avoid & Treat Heat Illness on the Trail


Before you know it'll be 110...million degrees outside and people will still be trying to hike in the middle of the day. There's a reason you don't see animals out at that time. * jus' sayin'

Cooking a late breakfast in the desertDehydration & heat exhaustion are killers on Arizona trails and easily preventable with some simple habits. Here’s the facts.

Last year more than 500 people died and more than 3000 were hospitalized in AZ from heat related causes. These numbers have been rising steadily every year for well over a decade. Poverty, age and an array of other factors play a large part in these devastating deaths and illnesses, but a significant contributor is unprepared hikers. Folks that just aren't ready for the extreme heat when they head out to enjoy the great Sonoran Desert.

Day hikers alone account for about 300 rescues every year in AZ, many of them right here in the Phoenix Valley mountain parks. Rescues in city parks? Yes. It happens year-round, multiple times a day April through August. People rescued that are not “injured” or lost (they are literally surrounded by city) but are dehydrated and succumb to heat exhaustion and cannot move. This is overwhelmingly avoidable.

Dehydration, if not treated can quickly turn into heat exhaustion which is a dangerous condition, especially for children and the elderly. If not treated immediately, heat exhaustion can quickly become heat Stroke, which is life threatening and requires serious medical care and hospitalization.

For outdoor activities this is almost entirely preventable and can be treated easily if recognized early, by following a few simple directives.




Symptoms of Dehydration:

  • Increased thirst
  • Dry mouth, lips, eyes
  • Increased sweating
  • Headaches, nausea
  • Irritation, fatigue, disorientation, dizziness
  • Muscle cramps
  • Lack of skin turgor, i.e., skin “tenting”
  • Lack of urine and/or dark urine
  • lack of appetite

When someone in your party is tired, sweating a lot, has a headache, is nauseous or grumpy they are most likely, dehydrated. Treatment at this stage is simple.

The problem is that this will start a cascading amount of cognitive impairment, i.e., bad judgement. People start making bad choices when dehydrated and hot. It's easy to miss, especially when that person is... you.

So how do you treat someone at this stage?

Learn more about our 10 Essentials


Resting in the shade of an emergency blanketTREATMENT OF DEHYDRATION: 

  • Get in the shade and rest. Just 15 minutes in the shade drinking water is often all it takes for recovery.
  • Drink water and, if it's bad, eat a little salty snack or add electrolytes to the water.
  • Maybe throw a wet bandana around they're neck.

If you've done all this and they're not feeling better in 20 minutes or so, you should:

  • End the hike and get to a cool air-conditioned place
  • Continue to sip water and Electrolytes
  • Monitor the condition. If it gets any worse or isn't better in 30 or 40 minutes, call 911 and get medical help.

You do not want it to get to this point so resting and hydrating early and frequently is the key.



PREVENTING DEHYDRATION is even easier. Here's how:

  • Before you head out, make sure you have eaten a regular meal including drinking water.
  • Dress in light loose clothing and consider a wide brim hat. This provides a micro-climate of shade for your body. Sunscreen or long sleeves also help.
  • Don’t hike in mid-day sun. Early or late in the day is best. Not only do you avoid the hottest part of the day but you’ll see and hear more wildlife.


  • At the trailhead, camel up at the car. Drink your fill Before you start hiking. This will set you up for a healthy hike.
  • Take Extra water and drink regularly, even if you’re not thirsty. Thirst is a very bad indicator of hydration. Flavoring the water with an electrolyte mix you enjoy might make this more enjoyable and helps replenish needed minerals.
  • Check children’s water bottles frequently to make sure they are drinking. Try an electrolyte mix they enjoy (test this BEFORE the trip to be sure they like the flavor).

And lastly,

  • When your water is half gone, your hike is half done, it's time to head back. It’s going to take at least as much water to get back as it took to get wherever you are.

That's it.

These things are simple & easy to do and, unfortunately, even easier to skip.

It takes 15 minutes to recover from dehydration. It takes days in a hospital to recover from heat stroke, IF you survive.

So… if you experience grumpy headaches and thirst,

  • Rest in the shade... Before it gets bad!
  • Drink water
  • Wet a bandana and put it around your neck

Here in the desert, we have a saying for people who go out on a hike with only one tiny bottle of water… "Bye."



  • Proper clothing for conditions
  • Water in the car
  • Enough Water for the hike AND a little extra (1 liter per 2 hours PLUS .5 liter minimum)
  • Bandana or cloth


ElectrolyteCamelbak Hydration Pack

[The Arizona Hiking Shack is all about your safe and responsible enjoyment of Arizona's trails. Anyone mentioning the "Pro Tip" in this article will get 10% off the purchase of any hydration product at the Shack from now ‘til the end of

summer 2021.]

The Arizona Hiking Shack, 3244 E. Thomas Rd, Phoenix, AZ 85018




If a dramatic natural disaster like a hurricane or tornado hit every single year for decades on end and took the lives of 300+ people with more than 2000 hospitalizations, every single year, an emergency would be declared and steps would be taken to mitigate it.

In Arizona, we have just such an ongoing disaster. Let’s call it a natural Disaster. It's just not as visually dramatic as a snow storm or flood, but it has hit every single year for decades and in the last five years has more than doubled in the number of people it affects. It lasts for 5 months every year and is getting worse year after year.

It's the heat. And yes, it's a dry heat.



Here's some science wonk for ya. (This is an extremely simplified explanation but it's an interesting way to look at what happens to you in the desert.)


Temperature tries to equalize. Meaning the heat from something hot will transfer its heat to anything near it that is cooler. This is called Heat Transfer. We use this law of thermal dynamics to cook. The mass (and BTUs) of fuel needs to be greater than the mass of the item you are cooking. (There's some equations and other factors for this but I said this is a simple explanation.)

So anyway...

In the desert, during summer, the temperature is often over 110 degrees Fahrenheit and can reach 120 degrees. Direct Heat from sunlight constantly heats things like sand, rock and car bodies to 140 degrees or more. These things then give off Radiant Heat, which is radiating off of them heating the air and anything else around them which are cooler. Then the air itself is hot and produces Convective Heat which is the main way heat transfers to liquids and gasses (spoiler alert, you have a lot of liquid in you). Lastly, the Direct Heat from the Sun bounces off lightly colored rock, dirt and sand causing Reflective Heat bouncing up at things (you), heating them from the opposite side than the Direct Heat. There's just a lota heat.

What does all this mean?

Basically, the Sun, rock and air (all massive things), can be 120 degrees or more. You are 98.6 degrees (and relatively tiny with little mass). What is all that massive heat going to transfer to? ... You!

Direct, Radiant, Convective and Reflective heat is difficult to get a break from in the Sonoran Desert. Without a break from it and without constantly replenishing your body's cooling system with water and electrolytes (vital minerals), your body will shut down in 3 to 6 hours in the mid-day sun, depending on your health. Your body becomes unable to keep up in the presence of all that heat. "Shut down" means serious muscle and brain damage directly followed by death.

And that's not all.

The dryness of the environment (normally single digit humidity) in addition to all this heat means that your body is not capable of producing enough sweat to cool itself. (Our sweat evaporates faster than our bodies can produce it here.)

And as if all that isn't enough, (Isn't this fun?!)

It doesn't even take this much heat to do all this. The above is an extreme example during the worst days of summer. All this happens regularly at temperatures much lower (just a little slower depending on your health). We see rescues for dehydration and heat exhaustion on days of just 90 degrees all the time. Why? Because people are not aware or prepared. The "nice sunny weather" can fool people with its appeal. Residents get complacent and visitors think it's a similar environment to home. It's not.


Drinking water and resting in the shade to cool your overheating body is the only option you have in this environment. Even the shade under a creosote bush can be 10 - 20 degrees cooler than being in the direct sunlight. Take a break, have a drink and enjoy the majestic desert. In 15 minutes your back on the trail.

Pro tip: Frozen grapes are an awesome wet cooling snack on the trail.

If you’d like to read more on this subject…


If you want more practical know-how and info for adventuring outdoors check out our classes at

Be safe out there.

Ian James of the Arizona Republic has a very good article on this. You can read it here.