I’m hiking in 90°F weather, halfway through a three-day, waterless trip. I accidentally spill the rest of my water. But my bladder’s full. Is there any way to make my urine drinkable? Filtering? Boiling? Or is it always going to be undrinkable? –Angela Schmidt via Facebook
What exactly do you mean by “undrinkable”? Kids in the UK have been known to sip their pee after watching Bear Grylls do the same on TV, with no lasting ill effects beyond their parents being very, very disturbed.
But that only works if you’re well-hydrated, and that’s not what you’re talking about here. Despite what you saw on TV, pee is even more full of salts and minerals than seawater, and drinking it will suck the life out of you faster than a bayou full of leeches. And a regular backpacking filter will do you no good. Your only hope is to evaporate the water out of the urine, then collect it.
Pee in a large container, apply heat, catch and condense the vapor, and funnel that clean water into a second container. Now, you’ve got two options. If you have a stove or a campfire, tinkle in your cookpot, put a cup inside (on a flat rock), cover the whole thing with your lid inverted so the handle points into the cup, and boil away.
Or build a solar still: Dig a hole about a foot deep, then add urine and any greenery you can find. Stand a cup in the center. Spread plastic over the opening, pull taut, seal the edges using rocks and dirt. Use a stone to weight the sheet over the cup so the water drips into it.
The stove is faster; the still might help you get extra water out of the soil. Both will only get you a small fraction of what you put in. Either way, the water will still taste like pee. So there’s some justice in the world after all.
When you’ve run out of water is it better to hold your pee or let it flow? –Kyle Lintern via Facebook
Sitting around thirsty and needing to pee seems double dumb to me, but I asked Dr. Paul S. Auerbach, a wilderness medicine expert for his say on the matter. “Water that sits in the bladder has already been discarded by the body and will not be reabsorbed,” he says. See that? Always listen to your mother.