Think dehydration and you probably imagine sweating profusely in sweltering temperatures in shadeless terrain. But the most dehydrated I’ve ever been was after making a simple mistake while winter camping in Tongariro National Park.

It wasn’t that we’d spent the night on the Summit Plateau. That was incredible. No, we had forgotten to keep our water inside our sleeping bags and our entire supply, in two three-litre water reservoirs, froze solid.

Compounding matters was our gutless stove that had no business being used at that altitude in the middle of winter.  Half the fuel canister had already been wasted as we tried to boil water for our dinners. Melting enough snow for the day ahead was out of the question.

Initially, we didn’t give a second thought to the lack of liquid. It was freezing and we were happy to be on the move. But by mid-morning, we were getting pretty warm.  Sweating even. Frustratingly, as hot as we were, our water remained frozen.

By mid-afternoon, our thirst was intense and all-consuming. There was water everywhere but it was white and none of it could be drunk. I became exhausted and walked extremely slowly. I constantly scanned the route for places where we might find running water. I made poor decisions. I took my crampons off at the first patch of scree despite much more snow being a few metres further along the ridge. I slipped and hurt myself.

We didn’t find a stream until late afternoon, when we were below the snowline proper. We fell to our knees and scooped great handfuls into our mouths. It was as if we’d crossed the Sahara.

By that stage our trip was basically over, though we didn’t know it just then. We carried on for another hour before finally calling it quits and set up camp overlooking Lower Tama. Our grand plans of traversing to the Tongariro Alpine Crossing were done for, all because we’d not had enough to drink.

That’s my dehydration story. You can read Shaun Barnett’s much better one on p56 and never forget: you need much more water than you think.