In the wild, you can survive a month without food. Without water, you might not survive the weekend.

They say you can “last three days without water,” but in reality, death can come much sooner in the wild. In hot, sun-baked conditions, fatal dehydration can develop within hours, and early symptoms—headache, nausea, and confusion—only make it harder to save yourself. If day hikers bring water at all, it’s usually a single small bottle, around half a liter, nowhere near enough to last a day off-trail if something goes wrong. It is therefore critical to find another water source to stay alive when lost. There’s one major problem: most surface water in the U.S. and Canada that humans or animals use is contaminated with Giardia, bacteria, and human enteroviruses like hepatitis. The combination of intestinal infection and dehydration is devastating to the human body. It becomes a matter of life and death not only to find more water, but to render it safe to drink. ¹²³

That’s why every Jackpack Gear kit starts with the same baseline: a LifeStraw. The LifeStraw’s 0.2-micron hollow-fiber membrane removes 99.999999% of bacteria and 99.999% of parasites without chemicals or batteries, and it’s rated for roughly 4,000 liters of use. It’s small, light, has a long shelf life, and it lets you drink directly from the source providing you significantly cleaner water to keep you alive when your sources have run out.⁴⁵

The Trekker kit adds real capability for contaminated water by including Chlor-Floc packets. Chlor-Floc is a combined coagulation–flocculation plus chlorine disinfectant originally developed and fielded by the U.S. military; with 30 packets, and each packet is designed to treat about 1 liter of water. The flocculant grabs fine silt, organic muck, and attached microbes into heavy clumps that settle out, while the free chlorine kills the remaining bacteria, viruses, and protozoa. In lab testing, Chlor-Floc–type tablets have shown roughly  99.9999% reduction of bacteria, 99.9% reduction of Giardia cysts, 99.99% reduction of rotavirus in cold, dirty water when mixed, settled, and decanted properly. That makes truly bad sources—silted pools, floodwater, stock ponds—far safer to drink. Once you’ve let the floc settle and then either drink through the LifeStraw or decant carefully off the top, you’re using the gold standard of water decontamination.⁵⁶

The Expedition kit assumes you may have no obvious water at all. That’s where the transpiration bag comes in. In dry country with live vegetation, slip the clear bag over a leafy branch, shake it first to knock off bugs and droppings, and seal it; as the day heats up, the plant’s own moisture condenses inside. In good sun with a big, non-toxic leafy branch, a large bag can produce around 2–3 cups of water, sometimes more, over a 6–8 hour daylight period. The condensed water is essentially contamination-free and does not require further purification. The same bag also works as a lightweight container when you do find water, so you can haul or cache what you’ve managed to collect. ⁷⁹

Your water plan starts before you ever get lost: know where you’re going, know where the water is supposed to be, and if the day is brutally hot with no shade or cover, don’t go—or cut the day short. In real wilderness work, the rule is “If you don’t have it with you, you won’t have it,” so you bring the water you need and extra, plus ways to treat whatever you find. On our jackets, the utility loops along the hem are placed so you can clip carabiners and hang extra bottles when you wear it around your hips, so you actually can carry that extra water instead of leaving it in the car. Once things go sideways, the priority is shelter and body temperature first, then water: stay in the shade, move as little as possible during the heat of the day, and do any necessary walking at dawn, dusk, or at night when it’s cooler. Morning dew wiped off grass and leaves with a bandana or towel can be a drinkable source. In a real emergency, questionable water is still better than none at all; a doctor can treat Giardia later, but nobody can fix dead.¹²⁸⁹

References

1. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Heat Illness: 2019 Update. Wilderness Environ Med. 2019;30(4):S33-S46.

2. Wilderness Medical Society Clinical Practice Guidelines for Water Disinfection in Wilderness, Travel, and Austere Environments. Wilderness Environ Med. 2019;30(4):S100-S120.

3. Backer HD. Water disinfection for international and wilderness travelers. Clin Infect Dis. 2002;34(3):355-364.

4. Vestergaard Frandsen. LifeStraw: Technical Specifications and Performance Data. 2023.

5. U.S. Army Public Health Command. Water Disinfection: Chlor-Floc and Other Field Water Treatment Options. Technical Guide 312, 2015.

6. Lantagne DS, Yates T, Blount BC, et al. Efficacy of flocculant/disinfectant point-of-use water treatment for reducing exposure to waterborne pathogens in developing countries and emergency settings. Am J Trop Med Hyg. 2010;82(2):291-300.

7. Forgey WW. Wilderness Medicine, 7th Edition. Rowman & Littlefield; 2021.

8. Centers for Disease Control and Prevention. Emergency Water Supply Planning Guide for Hospitals and Health Care Facilities. 2012.

9. Auerbach PS, Cushing TA, Harris NS, eds. Auerbach’s Wilderness Medicine, 7th Edition. Elsevier; 2017.