Backpacking in Extreme Heat: 9 Lessons From a Triple-Digit Summer in the Sonoran Desert

I‘m no stranger to backpacking in extreme heat. I’ve spent my summer trekking across the mountains and valley floors of the Sonoran desert during the hottest months of the year (in what is shaping up to be the region’s hottest summer on record).

My backpack thermometer hit 108 degrees every day in July, and June wasn’t much cooler. But I haven’t let that stop me from taking on My Sky Island Traverse. (No, not the Sky Island Traverse. This is a different route I put together linking up the southwest’s Madrean Sky Islands over the span of a year to study biodiversity!)

Ed. note: The information provided in this article is for informational purposes only and does not constitute medical advice or a recommendation to hike in extreme heat. Hiking in extreme heat can be extremely dangerous and is not recommended. Always assess your own abilities and consider the risks before undertaking any outdoor activities. When in doubt, stay home and wait for cooler weather before hiking.

So much biodiversity! So little time!

 Along the way, I’ve learned a ton about what to do and what not to do to stay safe from the heat when backpacking in its extremes. Have I made a couple mistakes in the span of hundreds of miles? You bet your booty I have! Luckily I have never made the same mistake twice, though, as the desert is quite unforgiving.

Stoked and full of vigor one month into my traverse!

Before I get started, it’s important to acknowledge that backpacking in extreme heat is not recommended and I am not suggesting you have this kind of adventure. A lot can go wrong when it’s this hot out, and people can and do get sick or die from hiking in extreme heat. The safest decision is always to stay indoors and wait for the heat wave to pass before hiking.

But if you’re someone who, like me, can’t resist the call of the desert, I’d like to impart my wisdom to you so that your chances of doing it safely are higher.

Tips For Backpacking in Extreme Heat

From the obvious to the not-so-obvious, below you’ll find all the tips I’ve got for staying safe while backpacking in extreme heat. Many of us experienced backpackers tend to think we know it all or have been through it all. But the extreme heat of the desert is something else entirely. The sun is not like alpine sun, and the dry heat is not your friend.

I do not consider myself an all-out expert on backpacking in extreme heat conditions, but I’ve learned a ton about it over the past few months and have been surprised by just how challenging it is. Little things can turn into life-threatening things fast. So if you plan to backpack in such conditions, take these tips seriously so you don’t make some of the errors I have!

The beautiful sights of the desert in summer are truly something to behold!

Let Someone Know Your Plan

This tip is as basic as it gets. Don’t venture into the wilds of a desert (or pretty much anywhere else) without letting someone know what your game plan is, on the off chance that there is an emergency. It’s a simple little insurance plan that can make a significant difference in any backpacker’s life.

If you don’t have someone you can tell your plan to, I recommend calling and speaking with the local Forest Service Office, BLM Office, or whoever runs the land you’ll be on. Tell them your plan and they’ll likely be glad you did. And be sure to sign any trail or wilderness registers you pass. These are the first things SAR teams look at should they need to come get you.

Start Early

A lot of us adventurers are used to rising with the sun and getting going. But in extreme heat, you’ll want to start even earlier, in the dark, especially if you plan to have a long-mile day. The difference between desert early morning and desert late morning can be 30 – 40 degrees. Which, you know … that’s really significant.

A bonus to getting started early is of course seeing sunrise every day. And desert sunrises? My gosh are they something else!

During My Sky Island Traverse, I have generally been on the move by 3:30 a.m. every day since June. At that time it’s around 80 degrees, and by the time I’m looking for a place to siesta and settle down y 2 p.m., it’s 105-plus.

At first, the early mornings were hard to get used to. And starting at 3:30 gave me an odd amount of time to sit at camp in the afternoon without really knowing what to do. Mostly I ended up hanging out under the shade of the ironwood trees or hoping for a cool breeze so I could hang out in my open tent.

But I got into my groove soon enough, and now I usually spend the afternoons photographing various birds, bugs, and other creatures. And of course, just soaking up the desert. It’s a fascinating biome to be immersed in.

Ensure You Will Have Enough Water

One of the hardest aspects of backpacking in extreme heat is the whole water situation. They say for every hour you’re moving in the heat, you should have one liter of water. And uhhh… there are pretty much no water sources. So as you can imagine, this is a huge reason that anything more than a simple day hike — if that — is discouraged in very hot places.

Before I set out on my traverse, I cached a lot of water in many parts of my route where sourcing it would be an issue. And I wouldn’t recommend taking on something like this unless you could do the same, dear reader. The whole water situation can get sketchy fast.

Luckily, there are cow troughs in a bunch of places throughout the desert southwest. Where I’ve been in the Sonoran Desert, many of them are even mapped out and fell within my route.

It’s not pretty water to filter, but I’ve been pretty darn excited every time I come across a cow trough! It’s the perfect place to re-fill every water container and to take a little break. On especially hot days, it also can provide a bit of shade.

I find that consuming and carrying enough water have been two of the main hardships of this adventure. I am usually carrying five liters of water on my back, which is super heavy — about 11 pounds!

The extra weight sucks, but it’s worth it. Twice I have been in a ran-out-of-water situation, and I didn’t need to learn it a third time. I try not to worry too much about the rate at which I’m drinking, as long as I can tell my backpack is getting consistently lighter during the hiking portions of my day.

Bring Electrolytes

A lot of us are familiar with electrolytes and use them frequently. In the desert they’re a must. But it’s important to be sure you’re consuming the right kind at appropriate times.

This is one of those things that I got very wrong in the first two months of my hike. I didn’t know then what I know now: electrolytes need sugar to work optimally.

So if you’re setting off to backpack in the extreme heat, don’t use electrolytes that are sugar-free or sweetened with anything but sugar. Your body won’t be able to make great use of them. And eventually, you’ll feel completely dehydrated and unwell.

On the topic of electrolytes, you’ll also need more than a packet or scoop per day most days. It’s astounding how much the desert makes you sweat, even when you are sitting with your pack off. Replenishing your electrolytes is so important in these conditions!

Use Sun Protection

Sunscreen isn’t going to cut it. In extreme heat, it’s important to wear clothing that covers your body, and it’s a big bonus to wear clothing that has UPF properties. A wide-brimmed hat will be your MVP. And sun gloves? Yeah you’ll want those too.

There is a thing locals say here in Arizona: you can tell who has no clue what they’re doing based on how much of their skin you can see on a hike. And I’d have to agree for the most part.

The sun is blazing hot and it will absolutely fry your skin if you’re not covered up. This is another one of those things I got a little bit wrong initially. Thankfully, I corrected my clothing choice super fast and only got a sunburn one time. Also thankfully, that was in April when the sun wasn’t yet at its most brutal.

When I first started my big adventure, I did not wear a wide-brimmed hat. I wore this little hat. And wow was that a mistake! The sides of my face and my neck became so burned up. I had to have my husband meet me on an access road with a sun hat just days after snapping this photo!

If you’re a sun umbrella kind of person, you’ll want to bring one along on any super hot adventure. I have used a sun umbrella here and there on my traverse, finding it a little cumbersome with my big camera and lens strapped to my chest, but nice relief from the sun if I am hoofin’ it during the hottest part of the day. For what it weighs, I think carrying it along is worthwhile for those moments when it is desperately needed!

Go Slow During the Hottest Parts of Your Hiking Day

It’s important during the hottest times to slow your exertion levels down. By a lot. Something I noticed in very hot periods is that my heart rate gets way higher than it should be. This is because of how our bodies handle the extreme heat and the incredible amount of work our bodies have to do to stay functioning in it.

I was shocked by my body’s reaction. I thought I had backpacked through some very hot places in my time. But nothing has ever humbled me like this desert has, at least where my biology is concerned. There is nothing as odd as moving at a tortoise pace feeling groovy and seeing your heart rate hitting 115 beats per minute.

Listen to Your Body

Some days backpacking just isn’t going to happen. I’ve been surprised that on my traverse, there are days when I just know I need to stay put for a day or two. Days when I feel exhausted or something about my body feels “off.”

Because of the toll extreme heat takes on your body, it’s important to stay in tune with how yours is feeling. And then listen to it! The desert in summer is no place to push yourself or try to be a fast-pack hero. Plain and simple: listen to your body.

Like this precious snoozy bee, sometimes you just need extra sleep or to not be out making miles. On days like that, I dedicate a lot of time to making photos I would otherwise miss.

Reroute

Rerouting sucks. But it’s important to get good with the fact that you may need to in extreme weather. This happened to me when I was faced with beginning my traverse of the Rincon Range in July.

Not only is that range boiling hot, but it sees an intense amount of flash flooding during monsoon season, which hits full swing in July. I thought about sticking to my route until two days before I arrived in the Rincons. Only in those final moments did I decide that sticking with Plan A would be unwise and honestly ridiculous. So I changed course and turned my perfect circle into a “B” shaped route.

It’s important to be flexible backpacking in extreme heat. Sticking to a plan is not worth your health or your life. There is no shame in changing the plan or making adjustments to your route on the fly. It happens to the best of us!

Don’t Go Backpacking in Extreme Heat if You Have No Experience or You Aren’t Heat-Trained

Yes, my last piece of advice is an annoying one. It’s also the most important one, probably. The extreme heat of the desert is not to be trifled with.

As I have been busting my booty to do this traverse, I have been paying attention to hiker news online and have been dumbfounded by the sheer number of heat-related search and rescue missions, and heat-related deaths of hikers. Some of these folks have a lot of experience and they still end up in life-or-death situations.

Heat acclimation is a very real thing. And if you plan to backpack in the throws of desert summer, I would strongly advise you to take heat acclimation into account before you schedule your adventure out.

To do this, I followed the US Military’s heat training methods. It’s basically a regimen of hard work in the heat, adding a bit more time out each day for a couple weeks. It’s not something you can accomplish on a vacation.

My heat training came in March when I began doing daily training hikes and walks, knowing I would be kicking off my traverse hike in April. It was already hitting 80 degrees in March, so I simply would throw on my backpack and make a few miles during the hottest part of the day. By April I was feeling comfortable on 90-degree days with a 50-pound backpack.

Because of the time of year my adventure began, I was able to pretty seamlessly heat train with the seasons unbroken.

The desert in winter is incomprehensibly gorgeous. So if you can’t manage heat acclimation and decide a winter desert trip would be safer, rest easy knowing it’ll be glorious.

Finally, consider this. There is a reason everyone visits the desert over the winter. If time is not on your side to heat train, skip the extreme heat adventure. The desert is always beautiful and winter is a lot safer for adventuring!

Final Thoughts

Deciding to go backpacking in extreme heat is a really personal choice. In my case, the choice was simple enough because of my biodiversity project and proximity to the route. Would I prefer to not hike in the extreme heat? Most certainly! But it’s been an incredible learning experience to do it.

If you’ve done a trip in some intense desert heat, I’d love to know about it. And I’m sure other Trek readers would too. Drop a comment with your adventure tale!