This post may contain affiliate links.

Hiking in Hot Weather by Kevin Ortcutt

The Needles Canyonlands
The Needles Canyonlands

Like many others, my backpacking plans are dictated more by available time than by the weather outside! Getting on the trail means carefully orchestrating time away from all my “big kid” responsibilities. Once I request time off from work, get someone to pick up the kid, and sweet talk my wife into letting me go, I’m committed to that time no matter what mother-nature has in store. So when an oppressive 7 day heat wave scorched New England during my carefully orchestrated time away, I had to take extra care in preparing to handle the heat.

Last year, I spent some time backpacking out West during a heat wave. During that time, I learned many painful lessons about strenuous hiking and backpacking in oppressive heat. I thought it would be worthwhile to share some of those harsh lessons and detail what I did to prepare for a very hot few days on the Appalachian Trail in Massachusetts.

Wait Out the Mid-day Heat

The biggest piece of advice I failed to follow on a trip to the bottom of the Grand Canyon, was to wait out the mid-day heat! On relentlessly hot days, the middle of the day (Roughly between 11AM and 3PM) is exactly when you don’t want to be hiking.

My father, Uncle, brother and I got caught in an area known as “The Devils Corkscrew” during the heat of the day. The sun was unyielding and you could feel it ripping the energy from your body with every agonizing step!

The Devils Corkscrew” Bright Angel Trail, Grand Canyon National Park
The Devils Corkscrew, Bright Angel Trail, Grand Canyon National Park

When we finally reached the Phantom Ranch Campground (at the bottom of the Canyon), we quickly developed a new strategy for hiking out! We woke up at 4AM and were on the trail by 5. We hiked to Indian Garden campground before the sun could have its way with us and waited out the mid-day heat. Around 5PM when the sun was no longer directly facing The Bright Angel Trail we hiked the rest of the way out.

Backpack Weight

This probably seems obvious, but I have to admit I fell victim to carrying way to much weight in the desert. Purge your gear of any items that don’t make sense for hot weather. Do you really need a 35 degree sleeping bag or spare jacket when it’s going to be 70 at night? Do you really need a hot meal after being in scorching heat all day? Or is the cookset / stove just extra weight?

When I hiked down the Grand Canyon I had nearly 40lbs on my back. The following week, when I went into Canyonlands for a 40 mile solo trek, I purged over 12lbs from my pack just in gear that was suitable for New England but not for Utah.

I applied many of these packing principals to my section hike on the AT this week. I left home my Sierra Designs 35 degree sleeping bag (2lbs 10 ounces) and brought a 9 ounce fleece bag liner. I did not bring any type of cooking equipment (although I generally don’t).

Hiking in New England also offers the advantage of being able to carry considerable less water, bringing my pack weight down to 22.7lbs for 3 days and two nights.

Cotton Doesn’t always Kill

A cool trick a park ranger in Zion National Park showed me was to take a cotton shirt, soak it in a river, then put it in a zip lock bag and keep it in your pack. If you ever felt dangerously close to heat exhaustion, put the shirt on and let it cool you off.

Despite every instinct I had to stay away from cotton, I wore a cotton shirt on most days and took every opportunity to soak the shirt in streams. It did exactly what everyone back East warns you it’s going to do. It failed to wick moisture away from my body and therefore helped to cool me down.

It’s important to understand your environment. I don’t encourage anyone to throw on Jeans and your Red Sox T-Shirt to hike Mount Washington, but in the right climate, Cotton can be an asset.

On my AT section Hike I stuck with my normal moisture wicking cloths, however I did pack a light cotton T-Shirt. During the course of the hike I soaked it in streams and used it as a bandana.

Camel Up

Hydration is everything on hot days. When you start to get dehydrated your energy gets zapped, your judgment becomes cloudy and worse yet you could be setting yourself up for a dangerous and even life threatening situation.

For last week’s section hike, I started hydrating 4 days in advance. I tracked how much water I drank by refilling 1 L bottles. My goal was to drink 6 liters per day on the days leading up to my hike. The morning of my hike started with a 3 hour car ride to Western Mass, where I drank 2 liters of water. During the hike I carried 3 liters of water in a platypus bladder and drank almost continuously. When I stopped to fill the water bladder, I drank another full liter at the water source before setting out to hike again.

Cameling up at water sources not only helped me to stay hydrated, but it forced me to take longer breaks then I normally like to take. As eager as I was to keep moving, in temperatures exceeding 90 and humidity above 60%, breaks are critical.

Walking through marshland on the AT in Massachusetts on a hot and humid day
Walking through marshland on the AT in Massachusetts on a hot and humid day

Chafing Prevention

Perhaps the most unexpected consequence of the heat I encountered out West was chafing. This started after doing the Narrows in Zion (in and out of water) and became much worse going up and down The Grand Canyon. On my way out of the Canyon the reality that my chafing problem may derail the remainder of my trip was setting in.

I won’t go into the details of how heat caused my chafing or the horrendous shape my inner thighs were in, but I will pass along the two tips that allowed me to continue my Western adventure.

  1. Synthetic moisture wicking underwear! What can I say? I got cotton happy in the desert and one area where cotton may not kill, but can certainly be destructive is your underwear. Out West I bought rather expensive Under Armor underwear. Since coming home I have stuck with the “Starter” underoos I picked up at Walmart for $7 and they seem to work just as well.
  2. Body Glide – This stuff worked miracles and it’s now a permanent stay in my backpacking medical kit. I apply it before every hike no matter the temperature because that is one area I never want to encounter a problem again!

Other odds and ends

  • Make sure to eat frequently. Your body is working extremely hard to keep you cool which means your burning through energy very quickly. Keep refueling your body with salty carbohydrate loaded snacks.
  • Take breaks. I mentioned before that “Cameling up” forced me to take longer breaks then I normally like to. In hot temperatures,taking frequent breaks is extremely important in order to keep your body temperature down.
  • Learn the symptoms of heat exhaustion and dehydration.
  • Never miss a chance to go swimming! There is nothing more exhilarating then finding a cool mountain stream to jump into on a hot summer day!


  1. thanks for some excellent tips – very valuable as climate change increases the potential for weather extremes.

  2. What about electrolyte supplements? I found them necessary on my recent Arizona Trail through hike.

  3. A well written, good and informative article Kevin. I do want to expound on Thomas Lafleur’s excellent question about the need for electrolyte supplements when hiking in excessive heat environments.

    I do quite a bit of hiking in desert climates and electrolytes play a vital role in maintaining homeostasis within the body. Water alone is “insufficient” to replenish the amount of electrolytes loss from sweat due to hiking in excessive heat climate. One can drink sufficient water but still feel sluggish and lethargic.

    Electrolytes regulate heart and neurological function, fluid balance, oxygen delivery, acid based balance and much more. Electrolytes are important because they are what cells (especially nerve, heart and muscle cells) use to maintain voltages across their cell membranes and to carry electrical impulses (nerve impulses, muscle contractions) across themselves and to other cells. Kidneys work to keep the electrolyte concentrations in blood constant despite changes in the body. For example, during heavy exercise, electrolytes are lost in sweat, particularly in the form of sodium and potassium. These electrolytes must be replaced to keep the electrolyte concentrations of the body fluids constant. There are periods at the end of the day that white streaks cover my entire base layer. If one licks the white streaks with one’s tongue, it is as if licking a salt block placed for horses or cattle, or even table salt.

    I also recommend a quality broad brim hat and bandana. Tilley manufactures an excellent broad brim hiker’s hat with a special removable cooling insert inside the crown that can be removed along the trail for soaking in water and re-inserted back inside the crown. The insert has evaporative cooling technology reducing the temperature inside the hat by an average of 20 percent. It was interesting to read the cooling trick told to you by the park ranger. In excessive climate heat at every opportunity where water is available at a creek or stream crossing I soak my bandanna (and now my Tilley crown insert) for evaporative cooling of the body.

    I learned decades ago the danger of hiking mid-day in the desert, even in the first few day of the month of May. I was in-bound mid-afternoon to the trailhead after hiking from early morning and decided to keep pushing onward to exit the trail. With no shade, the sun is merciless, “beating” down on you. I knew heat exhaustion was building inside my body as I can sense such build-up and feel the body heat inside me similar to viewing an overheating car alongside the road where the car’s engine is over-heated and you see the steam pluming forth from under the car’s hood. As I came off Pinto Mountain, in the Turkey Flats area, from having done a sunrise loop I saw the sun’s rays several miles away reflect off the windshield of my vehicle parked at the trailhead. So, I pushed on. I was about 500 yards on the desert floor from the trailhead and my body heat had risen dramatically. I looked for shade, but none around except for one cactus that was big enough that if I aligned my body properly I could get out from under the sun’s rays. I laid there and finished off drinking the rest of my liquids letting my body heat dissipate. After a period I got up and pushed onward the rest of the 500 yards only to find myself struggling badly. It was the first time I realized poignantly that it did not matter if one is 500 yards or 500 miles, one can died just as easily within a short distance in close proximity to their final destination. Fortunately I made it, quickly started the car’s engine, turning on the air conditioning and drinking the extra supply of liquids I had stashed in the trunk of the car.

  4. Comments about hiking in high humidity MO/AR/So.IL/KY/So. OH conditions:
    If possible, start before or at dawn. Don’t plan on hiking at the same rate as in cooler conditions!!! Plan shady routes. Wear broad brim hat. Stop at springs / spring-fed streams, and cave mouths and just chill. Bandana or piece of absorbent microfiber car-wash rag (my housework rags) dipped in cool stream then laid around neck – mmmm. Public-land caves are closed in Missouri due to attempts to reduce “white nose” fungal disease of bats, but it is still ok to sit near the entrance and enjoy that ~60 degree exhalation from the cave.

    Pre-hike hydration (avoid caffeine) is essential. Monitoring of water intake rate during hike is essential. I like at least one clear/translucent bottle with 100 cc volume marks for this reason. I keep an eye on the watch, and aim for drinking ~300 ml per half hour. That means I stop and drink every half hour whether or not I have been sipping in between stops, because almost always I have not actually reached 300 ml intake by the end of the half hour. Your optimum rate may vary. Urine color should be light gold.

    Food can provide some electrolytes nicely – I rather like roasted salted nuts or salted soy/broad/fava beans, available at your grocery store, “Trader Joe’s” type store, or other. I have never been much for flavored water electrolyte solutions, gels, or “Gu” packets for daily use – these are great for runners and bicyclists, but I am not in a hurry and can munch while walking. Still, I carry a Gu packet or two for emergency electrolytes.

    I wonder how much ammonium nitrate “instant cooling” packs weigh? Two of these might be a good thing for a hike leader to have on hand for sticking under the pits of (already resting in shade, drinking and Gu-sucking/chewing) overheating newbies.

    Sweaty, WEAK, headachy, cramping muscles, stumbles, nauseated, maybe dizzy, but MAKING SENSE – heat exhaustion. Stop!!! Shade, hydration, electrolytes, rest, careful observation – patient should feel better within 30 minutes, though not feeling normal. If no change in 30 minutes, plan for evacuation

    Hiker clearly DISORIENTED / CONFUSED? (as in, doesn’t know month or year, where or why they are out there, who you are, their own name, etc)
    This is the most important symptom of HEAT STROKE !!!
    STOP! Get patient in shade, strip, wet down and fan, and CALL FOR EVACUATION – NOW. This is a BRAIN/LIFE-THREATENING EMERGENCY. A single designated person should be observing the patient continually for changes while waiting for evac to arrive.

    Jerry, I used to ride horses, and learned quickly that they regard you as a walking salt lick.

  5. I’m a fitness hiker in the Arizona Sonoran desert. I am out there nearly every day, year round.

    First, since I am out there year round my body can gradually acclimate to the heat. As the desert gradually transitions to the insane heat of summer, I transition along with it. The first 80F day after a cool winter is a tough one, but by August I am unfazed by 105 – 110F. Hotter than that I reduce the miles and avoid steep climbs.

    I carry an umbrella for shade. It really makes a difference when it’s over 100F.

    For my normal hike (4.6 miles, 900′ elevation), I carry 3 liters of cold (refrigerated or iced) water. 100F to 90F I average 3 miles/liter. Hotter than that I get 2 miles/liter, less if I’m really working. If I’m doing a long hike (10 – 14 miles), climbing a lot, or it’s super hot I’ll prehydrate and carry an additional 1 or 2 liters.

    If I’m really sweating I’ll take electrolyte pills every couple of hours.

    I always have some kind of trail food, and take pains to eat while hiking.

    I wear long pants and long-sleeved shirts, and a hat with a wide brim and neck flap. It’s all wicking synthetics, but I might try a cotton shirt one of these days. It’s going to be 110F today; maybe I’ll try it after work…

    This works for me. If you are not acclimated, be extra cautious and conservative. The advice of the other commenters is excellent and will save your life.

    Even though I’m used to the heat I pay close attention to how I feel and if I see any danger signs like dizziness or anything out of the norm I rest in the shade for a while, or abandon the hike and return to the trailhead.

    I love hiking in the heat. Sane people are nowhere to be found, and I only rarely run into a few grizzled crazies on the trail. I highly recommend it. Just be careful. Especially in an extreme place like the Grand Canyon.

Leave a Reply

Your email address will not be published. Required fields are marked *