I have often talked to some people, posting on Facebook and in discussion, about how I survive hiking in hot weather. From small, local San Diego hikes to the Grand Canyon where I faced temperatures over 100 degrees Fahrenheit, to one day on a Pacific Crest Trail section hike where temperatures were over 110 degrees Fahrenheit with no shade in sight for many miles. Through all of this, I’ve picked up a lot of techniques, which I have practiced and modified, and continue to practice and modify. As this knowledge is useful, I am writing this post to describe some of what I have learned.
Disclaimer: As much as I would love to tell you that all of this could save your life, much of what I talk about in here could also kill you (no joke!). Following everything I outline here to a time that the temperatures drop below even just 50 could result in hypothermia–suddenly everything you’ve been doing to stay alive in the heat is killing you in the cold. Some things should only be used after a well thought out judgement call, which will require experience to make. Teaching your body to adapt and gaining the experience to utilize techniques to combat the heat is not something that should be done suddenly and harshly. Work your way up from small, safe hikes in safe temperatures, with more than enough water and survival tools on hand. Experiment. Get to know your body and how it responds to heat and furthermore to exertion in heat. If in doubt, it is better to cancel plans and stay alive. Only with experience can you truly know how to hone these techniques to your body. On the upside, the advantage of that experience could save your life when you least expect it–Murphy’s Law.
The most important thing about hiking in hot conditions is to know what you need to be cautious of. In the heat, the list is pretty simple: Dehydration, Heat Cramps, Heat Exhaustion, and Heat Stroke.
Rather than go into it myself, I’m going to refer you to Mayo Clinic’s articles about each.
Dehydration is the first thing you’ll want to constantly combat.
Heat Cramps will also start to be a possible first sign that you are entering dangerous territory (note: not everyone gets heat cramps before worse things start occurring!).
Heat Exhaustion is when you really need to stop and figure out how to cool yourself down. If you reach the earliest stages of heat exhaustion, you need to stop its progression immediately. Even just a small headache in the heat is nothing to play around with.
Finally, Heat Stroke is a full medical emergency. You need to get medical attention ASAP if you reach this.
These are larger concerns than the wildlife, food, etc. Such things can quickly become major concerns, but more people die from the short list above than any other factors in hot conditions.
What To Do In The Heat
Knowing that heat can well kill you, what do you do in it to stay alive? Below, I outline some tips, which can be practiced to figure out what works for you and what does not. You may find other tips elsewhere, and you should feel free get creative–just get creative in a safe environment and take what you learn with you from there.
Reduce Heat Gain
It is hot outside. Clearly, the first thing you want to do is reduce the amount of heat that you’re gaining!
- SHADE. Always keep your eyes peeled for usable shade. Always know where some is nearby, if there is any at all, and go to it immediately. The more you are there, the safer you are. The source of the shade is blocking the sun’s direct radiation from hitting your skin. The ground tends to be cooler, reducing the heat you’re picking up off of the ground.
- SHELTER. It can be extremely important in the heat (even more so if it is raining!). In fact, blocking a hot, dry wind can be exactly what you want in some conditions, as that hot, dry wind might be sucking the moisture right off of you faster than it can possibly cool you. You do want some air movement in your shelter in order to lose your own body heat, but don’t get caught into thinking that the hot, dry wind outside is always your friend–it can be a terrible enemy!
- REST. Avoid hiking in the hottest part of day, usually between 11am and 4pm. Seek reliable shade and cooler microclimates and just rest. If you can find any legitimate reason to hike in that timeframe, you should still stop and rest more often. When you are exercising, you are producing your own heat gain metabolically, and you are more likely to be in the sun, picking up even more heat. At the very least, take regular breaks–some say 15 minutes for every hour, but I would caution to err towards more than that until you have ample experience. Even if you can’t find shade, find the coolest plot of land (or carry a small pad) to sit on, and rest there momentarily. It is better than not resting at all.
Ideally, you don’t want to work anything over 60% of your exercise capacity–again, I would err towards staying below 50% even. This will keep you from developing too much of your own body heat, and also promotes tapping into your fat reserves instead of the energy reserves in your muscles, meaning you can last longer and go further.
- CLOTHING. Have proper clothing. I go into this further later.
Increase Heat Loss
It’s hot outside, and you’re building your own body heat by exercising. You want to lose that body heat before it gets compounded by the heat of the day.
- POSITION. Increase the amount of surface area you have exposed to the world and decrease your volume. Don’t get naked. Just splay out a bit more. This decreases how much your body heat bounces around itself and increases how much gets dumped out into the air around you.
- STAY WET. If you can stay wet, then that wetness can evaporate, cooling you down. This is how your sweat works, and is your saving grace in the heat. I go into some techniques based on this later.
- FIND COOLER AREAS. If you can find cooler areas and cooler ground, with ample air movement (not that hot, dry wind that negates your wetness), you can lose more of your body heat to the stuff around you. From shade to cooler ground and cooler microclimates. Find them and rest in them often.
- CLOTHING. Again, proper clothing can help heat loss. I go into this further later.
Stay Hydrated, Aware, Positive, And Not Stupid
Some basic essentials if you’re going to survive hiking in hot weather.
- STAY HYDRATED. The basic wisdom is to drink, drink plenty, and drink well before you think you need to. Many people go by the rule of “If you’re thirsty, you already aren’t drinking enough!” That doesn’t work for everyone (it doesn’t for me), but it’s a great place to start until you are absolutely confidently familiar with your body. The best gauge is your urination. You want to be urinating often, in ample amounts, and you want your urine to be clear. Ignore common thought that it can be lightly colored when you’re hiking in the heat. You want it clear if you want the absolute best chance at survival.
Here, it is worth noting that it is possible to lose far more water from sweating than it is possible for your body to absorb in the same amount of time. You might be fighting an uphill battle. So camel up early and stay hydrated from then on. When you are resting, camel up some more. Rest longer if you are having a hard time drinking more. Hydration is an absolute necessity, especially if you are in hot, dry conditions.
- EAT WELL. Salts! Salts! Salts! And carbs, and fats, and some proteins. Eat balanced. But you’ll be losing a lot of salt in your sweat, and if you are only replacing the water, you can fall into hyponatremia, or low sodium, which can mimic heat illness. It’s much harder to have too much salt hiking in the heat than it is to not have enough. If you reach the point that salt is tasting bad (simple indication that your salt levels are getting high), force down more water and just focus on your less salty treats for a little bit. Above all, learn your body and what your body’s needs are–and know that this can change, especially as you adapt to new conditions over time.
- ELECTROLYTES. If you eat well and are well adjusted, you might just be fine here. However, I like to carry at least one canister of electrolyte tablets to throw in my water, just to be safe. When I first started adjusting to the higher heats, I used them a lot. Over time, I found I didn’t need them as much as I was using them, especially as I got better about eating well.
- STAY AWARE. Staying alert and aware of your environment can save your life. You need to know where shade is, if any is available, and if any environmental threats are coming your way. Furthermore, you need to be aware of your body and your mind. If you so much as begin experiencing dehydration, heat illness, or hyponatremia, you need to stop and address that immediately. I even have the habit of routinely checking my pulse when I’m hiking in the heat. Don’t let fear, anxiety, and/or adrenaline in. If you have any of that, you need to stop, sit down, clear your mind, relax, get into the moment of right here, right now, and get totally calm–at least as close to it as you can.
- STAY POSITIVE. See what I did there? This is the single most important thing. I like to complain at myself about the crazy things I do, I will admit. I always meet that with a sense of humor and a positive attitude. “It’s too damn hot!” I will exclaim and immediately laugh at myself over it. I’m known to be walking down the trail, singing silly made up on the spot songs. I have multiple one-liners I say to myself to give myself a quick perk up, such as “Let’s go!” shouted with confidence and conviction (even if I’m not really feeling it), or “Party on!” (I stole that from Cody Lundin, and IT WORKS). Literally ANYTHING you can do to keep a positive attitude, no matter what conditions you face. Just do it, and your chances of having a good, safe adventure increase dramatically.
- DON’T BE STUPID. There’s a million ways that people can be stupid. From cockily thinking you know what you’re doing–you NEVER know what you’re doing with the plethora of curveballs nature has available to throw at you–to smoking and drinking alcohol. Let’s cover some:
- DON’T BE COCKY. Be confident instead. Convince yourself that you can and will make it, but know that Murphy’s Law will take you down.
- RESPECT THE LAND. In every move you make. Nature doesn’t care who you are, and she can kill every last one of us if she so pleases without so much as a nanosecond of hesitation. Absolutely no one is exempt. She demands your respect, and that respect will keep you alive.
- DON’T INGEST STUPID SUBSTANCES. Don’t smoke. That should be obvious, but some of us are stubborn assholes (*smokers cough*mumble*smokers cough*). As much as it might sound nice, don’t drink alcohol either. Alcohol will interfere with your ability to stay cool. Just don’t do it. Be totally sober, clear of anything but water, healthy food (I’m not going to define that, but you need salts and carbs for sure), and a strong mind and spirit. Anything else is just stupid (*smokers cough*mumble*smokers cough*).
Gear and Clothing
The gear you’re carrying and the clothing you wear is going to be essential. I’m going to leave some specific items off of this list for the nice tips and tricks below. However, there is a saying: There is no bad day, only bad clothes. Take that with a grain of salt, but there is some wonderful truth behind it.
- GO LIGHTWEIGHT. The more weight you carry, the more energy you have to use, the more heat you produce to do so, and the more you have to rest, potentially setting yourself up to be in the worst places at the hottest time of day. You should be prepared to spend a night or two if Murphy’s Law decides to strike you down, but be realistic. Do you really need any of your cold weather stuff? Is it going to be that cold, even at night? Can you safely cowboy camp for a couple of nights in the area? On a day hike, if it gets to this, you’re more worried about survival than comfort; known overnight backpacking, you should still consider how much comfort you really need in the heat–a heavy pack in the heat is going to be even more uncomfortable than cowboy camping on a boulder for a night (I say this from experience).
- TAKE IT OFF! Your backpack that is. Stop and take that heavy bastard off regularly. Let your back and shoulders (and waist, if relevant) breathe. You might find this a wonderful feeling in itself on some hot days, as the sweat accumulated on the back of your shirt and has a chance to start evaporating finally.
- BASIC SURVIVAL AND FIRST-AID KIT. Have them. If you ask me, it’s stupid not to go out into the wilderness without them. You never know what’s going to happen. Your survival kit should be geared towards what you might need to survive (everyone’s should be different, and that’s an entire book). Murphy’s Law also dictates you will need that first-aid kit. Both kits: know how to use them, with knowledge and experience. As you build yourself up to hiking in hotter conditions for longer, you should be practicing your skills with these kits so that you are intimately familiar with them.
- PLENTY OF WATER, EXTRA FOOD. Bring more than enough water so you can stay hydrated. It’s heavy, but it will get lighter as you keep yourself well hydrated. Extra food is good to help you survive, but know that you can survive a while without it. If it gets down to it, though, that little bit of extra could at least brighten your attitude!
- LOOSE FITTED, BREATHABLE CLOTHES. You want your clothes to breathe, to let out your hot air from your body and let the air circulate through, around your body.
- LIGHT COLORED CLOTHES. Light colored clothes reflect the radiation from the sun, preventing the sun from heating you up. The sun’s radiation hits you directly, but also bounces off of particles in the air and nearly every object around you. Wear light colored clothes to block that out, as all of that radiation will increase your heat gain.
- WIDE BRIMMED HAT, SUNGLASSES. Keep that sun off of you, and out of your eyes!
- LONG SLEEVES? GLOVES? Light colored, loose fitted, breathable, long sleeve shirts, special “sun gloves”, and even loose fitted, light colored long pants can actually be a godsend in the heat. They will actually block out more heat than they capture underneath! I always wear a loose-fitted long sleeve, button up shirt, sun gloves, and actual pants meant for hiking. This is a system that does actually work!
- SUNSCREEN? If you get sunburned, your sweat glands reduce the amount of sweat you are producing, and that skin begins to absorb more and more heat. Plus the whole cancer scare. I don’t personally use sunscreen, because I block off my skin with clothing instead. You should absolutely do something about it!
- WET CLOTHES. Repeating myself here. Keep your clothes wet! Wet clothes, in a hot environment, is your own personal swamp cooler! The weight of the extra moisture is entirely worth it!
- COTTON?! Yes! Cotton! In hot, dry weather, cotton will not kill you. In fact, it will keep you alive! The bad thing about cotton is that it absorbs your sweat and stays wet. Wait a minute. Didn’t I say stay wet as an essential earlier? Yup. I sure did. In hot, dry weather, cotton stays wet, promoting a slower evaporation than other fabrics, which increases how cool that evaporation makes you and keeps your own body temperature down! Awesome!
- WHAT ABOUT WOOL? SYNTHETICS? In hot, dry conditions, stick to the cotton, if you ask me (a good number disagree). If the temperature starts dipping down, switch to your wool and synthetics, where those shine. If humidity and dew point starts rising but it’s still hellish hot… I’m sure there’s a point where the increased evaporation that wool promotes over cotton is a benefit in the heat and higher humidity. There is probably even a point where the rapid evaporation that synthetics promote actually comes in handy in really high humidity during heat. I always carry an extra synthetic shirt on me if I need to get out of the cotton for some reason, but I have only switched to it when I didn’t want to be wet any more. Try experimenting in safe conditions (be able to switch to the other if need be) and figure out what works best for you.
- WHY SO MUCH CLOTHING?! There’s some people who swear by wearing much less clothes (having some in backup, just in case, typically). I would only advise you to look at the Sunscreen option above, at least, because going out with minimal clothing and minimal protection from the sun just sounds totally insane! (In really high heat–as in over 100F–there’s also evidence to support that going the less clothing route can be dangerous, so be careful.) Go ahead and experiment. Maybe you lie at one of the extremes, or maybe you like more clothes in one spot and less in another. Test it out in safe conditions, see how it goes for you, and roll with it.
Some Cool Tricks
Just following the above well should increase your chances of having a good time and ultimately surviving while hiking in hot conditions. I can also add in some additional little tricks for you to experiment with.
- WET BANDANNAS! Bandannas are an absolute necessity in my hiking kit. I carry 7 or more with me any time I go out. Get one wet, wrap it around your head. Get another wet, wrap it around your neck. These will keep you cool. I’ve even talked to people who swear by wrapping wet bandannas around their arms and legs to help stay cool! Just make sure they’re a light color (white is ideal for this purpose). Plus, having a few extra on hand of different colors serves a multitude of other potential purposes!
- SPRAY BOTTLES. I always carry 2 spray bottles with me. Always make sure they are filled with potable, drinkable water. In the heat, I can mist myself with the spray bottles! This not only feels absolutely amazing, it acts in the same way that sweat does to cool me off, potentially reducing the amount that I need to sweat. Making sure to always have potable water in them also makes a source of backup water! You’ll have to weigh the utility of misting yourself versus keeping that backup water. Experience can teach you that best.
- STORE WET COTTON CLOTHES. I gave you my thoughts that cotton is pretty much the best in hot, dry weather. Well, even if you choose to stick to your wool or synthetics, I’ve met some people who keep a wet, cotton shirt in a plastic bag in their pack. The bag is to keep the cotton from drying out over time, and if they need a quick cool down, they can throw that wet shirt on and instantly feel a rush of cool across their skin. Or wear it like a bandanna, even!
- BREATHING. When you exhale, moisture comes out and evaporates into the air. In high altitude, this can create a pretty significant cooling effect. In lower altitude, it is insignificant. Additionally, this can increase your dehydration in a hurry under the wrong conditions (cold and dry). Unless someone has scientific articles to point you to why breathing one way is better than another, don’t believe them, though (there are 2 cases that matter: cold, dry climates, and if you are asthmatic). However, paying attention to your breathing can have a calming, meditative quality, which can keep your attitude up and awareness of your body on high during hiking, and that I totally advocate!
Other Notable Things
- BEWARE THE FEET. Blisters, specifically. People could argue all day about what shoes (or lack thereof) are best, what socks (or combination of socks, or just lack thereof altogether) are best, etc. I, personally, prefer a barefoot style trail running shoe, which I frequently take off and go barefoot. I also like to use silk sock liners and wool socks over that when I’m wearing the shoes. Often, with the socks, I’ll switch out to a fresh pair after a while of hiking. Others go in much different directions. Whatever you do, if your feet are sweating and facing a lot of friction, you may find yourself worried about blisters. Blisters suck. Try out a few things, see what works. Just be safe. And avoid those blisters!
- DON’T HIKE ALONE. Some of us crazy people ignore this. You really shouldn’t if the heat is getting bad. Sure, you can do mini mental exams on yourself, if you know how, and you can learn how to check your capillary refill and what all of that means. Nothing beats another human being at looking at you and knowing if you look like you’re in bad shape (except a different, more educated on the matter human being!), though. And if Murphy comes around, another person can totally save your ass!
- HOPE FOR THE BEST, PLAN FOR THE WORST. Have a plan. Allow yourself room to explore, by all means. At the very least, however, spend some time familiarizing yourself with maps. And take those maps! Expect and plan for the unexpected. Always be prepared for your plan to fall through and have backup plans ready. This goes for any hiking adventure, but is especially pertinent in hot (and cold) conditions.
I can guarantee you that there are plenty of additional points that could be added to this. A lot of this might seem like common sense, and hopefully it is. Some might have plenty of other cool tricks up their sleeves about hiking in hot conditions as well. It’s all about having fun, though. Don’t ever forget that!