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Hot climate activators standard liquid loadout

I am curious what activators in hot climates carry as a standard loadout and max load for significant hikes.

I am thinking about this because there was another death at Big Bend National Park shortly before my last activation this month. I have seen hikers with nothing more than a small water bottle in hot areas, which I think is risky. In the US at least the standard line is 1 gallon per person per day, but this is frequently insufficient in my experience with long hikes or bushwhacking. Just to be clear, that hiker that died was experienced in desert hiking and I am guessing it had everything to do with heat and not lack of liquids. I did not know him and am not criticizing in any way. In fact, I donated to his daughter’s Go Fund Me college fund since he had sole custody.

My standard summer loadout is 1.5 gallons for probably half the hikes I do in W5T western mountains. My last hike was 2+ gallons and I used it all and happened upon a spring and treated 2 more quarts just to be sure. I take about 40% volume as Gatorade and salty snacks. I would like to get info from others as I may address this with others or publicly.


Good subject Brent , My activating logistics is probably not really relevant to the topic as I do not activate in our summer season with 40c plus days. Most of the summits in vk5 I visit are on private property so I don’t bother asking permission as I know the answer. We also have closed parks during Fire Ban Season which is from November until March, so no entry to summits in parks on Fire Ban days. Temps over 35c or something like that. Autumn, Winter, Spring are my best seasons to activate so not much hydration problems for me. I usually take 1 litre of water on the hike up to 8km round trip or 2 litres on a couple hikes of 14 km round trip. Make sure I have a big feed before leaving my SOTA transporter and take snack bars and apples they seem to travel the best in my pack. That keeps my whole kit to about 8 kg including my antenna pole.
You did not say in your post how far you hiked to need so much water sounds like a long one.
Ian vk5cz …

I’d be interest to know about others too. For me, I usually pack 2 liters pretty regularly with another 4 in the car. I drink 1 liter on the drive there and 1 liter on the drive back with 2 extras in the car. 2 liters seems to be my sweet spot. Most of my hikes are under 6 miles RT or afford water refills about every 4-6 miles. For example, I hike the Grand Canyon every year, rim-2-rim, which is 24 miles. I only pack 2 liters for that. It obviously depends on where you can find water to filter and refill. I have packed 6 liters for a 10 mile hike with no opportunities for refills along the way and I ended up drinking 4 liters.

BTW I always carry some sort of water filtration system regardless for anything over 6 miles RT. It’s saved me a couple times.

I’ve done quite a number of short summer activations of 1-2 miles in 110+ F heat and still only drank about 1 liter (plus 1-2 in the car).

It seems like 1 liter for every 2 miles works for me in the heat.

Charlie NJ7V

Thanks for the comments guys. This is helpful in understanding what others do so I can provide guidance beyond my experience. I would like to work to break this fallacy of giving trivial consideration to liquids. I had no idea Australia had those access limitations. NJ7V the pre-hike hydration is smart and I do the same. Incidentally, that recent contact we had was 96-97 degree day and 1.75 gallons for the hike.

I do not calculate based on distance but typically by temperature and anticipated difficulty. Difficulty includes weight of pack, elevation gain, and whether bushwhacking. My wife and I hiked in central Texas once at 107F/41.7C with high humidity. I was consuming at a rate approaching a gallon an hour during fast-paced hiking. But my summer temperature in West Texas is typically between 80F/26.7F and 100F/37.8C. Typically rough terrain with no opportunity to refill so I go through a lot of liquids. So one peak was 10.6 miles in the afternoon on trail and I went through a little more than 3 liters. The 2+ gallon day I do not know distance because it was largely bushwhacking very tough terrain and lots of elevation gain. But it was a longer day at 11.7 hours.

It really depends on the temperature and length/difficulty of the hike. But if I think I’ll need more than 3 liters, I start to question if its a good idea to go out on that hike. The peak will be there in a few months when its cooler.


I live in the desert and activate mountains in the AZ strip regularly. My standard is 2 liters unless I go over 5 miles round trip, which does happen of course. I keep 5 gallons in the pickup, a couple of iced thermoses filled as well. Only once (in 180 activations) have I gotten nervous about not having enough. When I do go out in the summer in the desert, I plan so that I’m back at the pickup by 10am.

I’ve gotten close to a heat injury twice, but not caused by lack of fluids. I do not consider activations on days that will go over 104F or that will cause me to go into the afternoon under any circumstances in the desert in the summer (I activate solo and many times I won’t see another soul all day in the desert so I don’t take the chance).

I guess I should mention that I also hydrate heavily the day before summer desert activations as well, and do so before leaving as mentioned. I used to do many more to get the 3 summer-bonus points, but after MG haven’t done as many.

Mike AC0PR


KG5AUU it sounds like it was a challenging hike to that peak. I agree with you, temperature and difficulty are definitely factors to consider. After reading your comments I realized I actually calculate based on time rather than distance. I average 1 hour per 2 miles for most hikes but with increased difficulty it takes more time to cover the terrain. 1 liter per hour is a much better description of how I calculate.
Good points! I too see hikers frequently underestimating their water consumption
Charlie NJ7V

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This summer in Catalonia, Spain has been hot, temperatures around 38-40C and peaks over 42-43C.

I carry 2 litres into my backpack and the Steripen to esterilize water that I found.

Another thing for the hot summits is the Bonnie hay, to prevent the hours and hours under the sun don’t toast me.

I hike in the heat a lot and I tend to sweat a lot. I try to carry a good amount of liquid, both water and gatorade. Usually a minimum of 2 liters of water and a 20oz bottle of Gatorade, several more of each for longer hikes and when it’s above 100F. I had > 2 gallons with me for my 14-mile hike on Saturday but did not use it all. I learned early on that the 2.5 liter water bladder gets damaged when I’m also carrying radio gear, so now I normally take everything in plastic bottles. Except in the winter months, I normally freeze about half of the liquid before the hike. This serves two purposes, one to provide a good heat sink for the rig, and second to provide cool hydration when on summit and for the hike down.

There is almost never any water to be found when hiking in Southern Arizona, so it’s crucial to take enough. Like Charlie, I also hydrate prior to the hike. I also do a lot of running, and I believe that my body has acclimated somewhat to becoming termporarily dehydrated. I’ve actually weighed myself before and after runs and have seen as much as 7lbs of reduction from a long run (this is normal for long-distance runners). There is some great literature out there for athletes about dehydration and similar hydration issues (for example, “Waterlogged” by Tim Noakes). It’s important to know how quickly the body can re-hyrdate, as well as to understand the effects of electrolytes, risks of hyponatremia, etc. when participating in activities that can cause dehydration. But basically, the best thing to do is probably to carry more hydration than you think will be necessary. That way you’re covered if you under-estimate, but also you’ll have more if you have an accident or get lost; you’ll also have some to perhaps share with someone else who has not planned as well.

73, Keith KR7RK

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My wife is an ultra-marathon athlete, so her knowledge of 100 mile trail run necessities comes in very handy.

On every activation, hot or not, I take some fluids with electrolytes and nutrition. For long hikes for activation, a trail pack which has a bladder with nearly 2 liters of fluid. The fluid consists of water with electrolytes and other nutrients in it made by a company called Tailwind. I do not take food. At most, maybe a Clif bar or two. Eating only makes me tired.

As for clothing, since I was born and raised in a clothing optional home, and a minimalist at heart, if I am hiking in wilderness, I strip down as soon as I am clear of people. The only extra clothing I take are socks. If activating a site where people are around, I wear the lightest clothing possible- swim trunks or speedo made by “Cooltan” company. Their swimsuits seriously feel like nothing at all. VERY airy and cool to wear. My latino skin makes it nearly impossible to sunburn, so one application of sunscreen before leaving the truck is all I need.

As for footwear, I prefer the Hoka One One trail running shoes. SO much better than hiking boots! They are very light and airy, plus they have excellent traction and durability.

My radio equipment and accessories all fit in to a fanny pack worn around the waist or over a shoulder. If doing an HF activation, all that gear fits in a backpack.

This is good data guys. Thanks. I knew I would get some W7A and W6 responses. And I didn’t know Spain reached those temperatures.

I have data from non-SOTA hikers as well. What is clear is anyone who is experienced knows the necessity of liquids and the amount is temperature, terrains and time dependent. But the base guidance I would give from my experience and others is about what NJ7V concluded, about 1 liter an hour for hot weather hikes and adjust that according to temperature, terrain and fitness level. 2-3 liters per hike is a common standard but adjusted up for difficulty/length.

K6FRC you cracked me up this morning. I thought you were jesting at first as I envision a man running down the trail with nothing but the male equivalent of a g-string and small pack. But I believe you’re stone-cold serious. I hadn’t raised clothing but I also think that is highly dependent on environment and a material consideration for any hot weather hike. I would get hacked up where I hike as nearly every plant intends to poke, claw, stick or rip. I thought I lost a nipple on a hike by a sawing motion of sotol plant as I bushwhacked and that’s no joke. I routinely get bloody to some extent and have squeezed out agave needles three months after a hike. As a result of that and the sun, I take the opposite approach with full somewhat baggy clothes unless strictly on trail. Hence I look like a hobo, complete with snake gators and gloves.

This is starting a brief two miles on trail before bushwhacking through significant foliage and rock to get to the two full peaks at the rear of the center of the shot. This is the 2-gallon and nearly 12-hour day.

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Having recently moved from W3 to W6 I need to do some adjusting. I ran out of water the other day on a ~85 degree day on my descent and started getting worried. Around the time I got back to the car I realized I had stopped producing sweat and was glad to open the spare 1.5l bottle stored in the car.

I used to take 1L for short hikes in PA and 2L for longer summer ones. I thought grabbing 3L would be enough for a 5 mile hike here in CA but this just wasn’t enough. My pack takes a camelback but I’ve always been afraid to keep the radio gear next to a large water bladder but I think I’m going to add it back in, while keeping the 3L of water as well (1.5 liter bottles on the sides of the pack). That should get me to 5L. I’m also going to get some electrolyte mix (I’ve also heard pink Himalayan salt is perfect for this) for at least one of the bottles.

Stay safe - KN3O

On some longer hikes I have hand carried a “SPARE/EXTRA” gallon of water (sometimes frozen) to the halfway point of my hike and left it there, in the shade if available, for on the way out.

That cold water on the way back is really a treat, and I didn’t have to carry it up to the summit.

I seed the trail with water…



Believe it or not, this is an issue in the American Southeast, too. Even in these forested mountains, there are trails with limited water access en route, and during drier years those water sources can dry up entirely by mid-to-late summer. In the Southern Appalachians, I’ve experienced mountain temperatures with summer highs up to 90 F, although low to mid 80s are more common. As a result, for summer hiking I typically carry 4 liters of water, and on a recent activation with a 15 mile hike I started with 5 liters. I had only 1/2 liter by the time I got back to the car, so perhaps it was not excessive after all. My feeling is that if I run out of water before I get back to the car (where I keep an extra liter), I wasn’t carrying enough.

I envy someone who is at no risk of skin cancer and can accept sun exposure so freely. Having had a skin cancer removed already, I wear long, loose-fitting pants, a long-sleeved shirt, and a broad-brimmed sun hat, along with sunscreen on all exposed skin. Not all fabrics are UV-protective, so I pay attention to the fabric SPF rating. Given the rates of skin cancer in the US, this probably would be good practice for many others!

Yep, I’m serious. Have been a naturist hiker all my life. Several advantages. For example, I have never been bitten by a tick. Even on 104 degree days, it is completely tolerable.

So, for really hot days when doing a SOTA activation, if no one is around, then I hike naturally. For populated summits, the super lightweight “Cooltan” shorts or swimsuit.

73, Paul

If it’s hot and long, 3.5 liters. Normal 3. I don’t drink enough. I’ve run out of water twice on a hot day and I was miserable even though I only had 2 or 3 mi to go. Once was due to a leak and the other was my screwup. My normal year around load it is min 3. It’s a comfort thing. I don’t hike when it’s over 85 if I can help it, that’s misery by itself.

I keep water in the car and try to follow the rule if I run into someone else on the trail I can share and or carry enough layers, food, water to survive 24 hrs Incase I get hurt.

I’m glad to hear someone else is lugging enough “…to survive 24 hours…” It seems crazy to carry that extra weight, and yet I do it, too. I listen to a podcast that reviews accidents in mountain sports (mostly climbing) by interviewing the survivors and/or their rescuers, and asking them about lessons they learned. One of the most frequent is the need to carry extra gear that seemed like excess weight but was needed in the emergency. The sentiment usually is expressed as either “We were really glad we had our ____” or, alternately, “We were really sorry we were traveling so light and didn’t have ___ and from now on, I will be carrying it!”

The podcast is “The Sharp End” (https://americanalpineclub.org/sharp-end-podcast/ )

I am going to listen to that podcast. There are a lot of lessons. Ultimately though we have to exercise good judgment. I had summit fever on my last activation and got myself into a real pickle and couldn’t turn around without broken ankle minimum and probably much worse and questioned whether I could continue the climb but had no choice as I was on a ledge requiring strength to support me. Luckily I got up and there were trees I could tie to for the rappel. Otherwise I was radioing for rescue and spending the night up there. I don’t take extra water. I take enough to reasonably use for the planned trip and not die if I have to spend the night.

I considered a write up on it here but not sure it is of sufficient interest. Point being though that we can have the knowledge but if we don’t stop and consider we can get into a risky situation. I thought I could take the first ledge and did so, but I’m my exuberance for the challenge I didn’t consider the next potential challenges above that one.

When the subject of hydration, (or the risk of dehydration) comes up, ibuprofen should be mentioned.
Marathon runners gobble the stuff; (they call it vitamin I) Of course, they have folks on the sidelines offering them water, so they don’t have to carry it! Takeaway: If you have Ibuprofen aboard your body, and somehow get dehydrated, you will be in danger of renal failure. Google Ibuprofen / renal failure, and watch the pages come up. If you need something for pain, ask your doctor to recommend something else. Been there, done that; took 3 days in hospital to get re-hydrated.

Here in Europe I carry a maximum of 3 litres, which might last me 2 days at the most depending on the temperature. I aim to collect fresh water every day and drink from springs where possible.
73 de TF/OE6FEG/P