Here's a scenario I was faced with recently. We do a climb that involves going up to a mountain hut and sleeping there the night before summit day. There is no snow at the hut to melt for drinking water, so we have to carry up all our drinking water. This is in Mexico (on Iztaccihuatl), so we're buying water in bottles. Temperatures at the hut are forecast to be below freezing. On the night before summit day, we can sleep with water bottles inside our sleeping bags to keep them from freezing. But on summit day, we need to leave most of our water at the hut, to which we'll return. Although we can leave these bottles inside sleeping bags and hope they won't freeze, we can't count on that, so the expectation is that when we get back to the hut, all of our water is frozen.

In this type of situation, what good techniques are there for getting the water unfrozen?

The best plan I was able to come up with was the following. Bring up a plastic bucket. Before heading up on summit day, remember to pour out some water into a pan, and more into the bucket. When we get back to the hut, melt the frozen water in the pan, then use an ice ax to chop more ice out of the bucket and melt that as well. (A variation on this plan would have been to not use a bucket, but use hot water in the pan to thaw out the frozen water bottles, by dunking the water bottles in the hot water. I think this might have been much too slow, however.)

I didn't actually get a chance to try this plan, because conditions changed. (A big storm came in, and dropped a lot of snow at the hut, but the storm also prevented us from doing the climb.)

[EDIT] Some of the answers and comments have talked about using big pots, building campfires, and hanging things from above. My question is about mountaineering, so none of that is applicable. We're above tree line, and the heat source is a stove. Although in this particular situation we might have been able to hang things from above (because we were going to be in a mountain hut), that would not be possible in general.


2 Answers 2


When I have frozen water bottles (usually plastic Nalgene bottles), I melt them by putting them in a pot of hot water. It doesn't take too long to melt the ice to the point you can get it out of the wide-mouth bottle. Then you can just dump the ice into the hot water. (As you get more water in the pot, make sure to ladle it back into bottles so the pot doesn't overflow.)

Of course, that means you need some water to start with. I like your idea of leaving some water in your pot to freeze. You could also bring along a flexible cup or three to use as ice-cube molds overnight, then use those as your starter water.

  • Am I visualizing correctly that you have a pot big enough so that a 1-liter nalgene bottle floats in it, on its side? Do you have problems with the plastic lid on the nalgene bottle hitting the side of the pot and melting?
    – user2169
    Commented Jan 18, 2016 at 20:26
  • I usually stand the Nalgene bottle up in the middle, but you'll want a good-sized pot. I bring a big pot for boiling water, anyway. (Get one with a handle that attaches to the pot, not the lid, and that goes over the top so you can suspend it over a fire pit. Something like this is perfect.) Try to keep anything not submerged away from the sides of the pot. The submerged bits won't melt, though.
    – samglover
    Commented Jan 18, 2016 at 20:30
  • My application is mountaineering, so it's not possible to bring a huge pot like the 10-quart kettle in the amazon link. Our source of heat is a stove, not a fire in a fire pit.
    – user2169
    Commented Jan 18, 2016 at 21:09
  • The 10-quart pot was just an example of the type of pot I'm recommending if you might want to suspend it over a fire. Otherwise, use whatever type and size of pot will fit most of a Nalgene bottle. I use a 4-quart version of that pot, which fits pretty around the end of many sleeping bags in a stuff sack. But you really only need enough water that your stove can keep it hot while the frozen bottle is in it. Just go to an outdoor store and start putting Nalgene bottles in pots to see what might work for you.
    – samglover
    Commented Jan 18, 2016 at 21:26
  • 1
    My MSR pot holds exactly one nalgene full of water. And I take it on every camp I go on. A small pot to boil water is exactly what you need above the treeline in sub zero temperatures.
    – ShemSeger
    Commented Jan 19, 2016 at 3:57

When I'm winter camping I always leave my water in my pot over night, so all I have to do in the morning is turn the stove on and let the ice melt. If I want water for later, I'll typically boil it, then leave it in a good thermos, which will keep it liquid at -15°C for a good 24hrs.

Though not very practical, your idea with the bucket will work, just keep in mind that chopping away at ice in a frozen plastic bucket is an easy way to crack open the bucket. Alternatives to your plastic bucket idea would be to bring freezer bags, they'd be lighter to carry, and easier to retrieve your ice from. If you want to get fancy, you could bring a silicone container, like a silicone pot that you could easily peel off you brick of ice.

If desperate, you may be interested to know that it is impossible to burn a container filled with water. You can literally place a paper cup in a roaring fire, and the water will all boil out before the cup will burn:

enter image description here

You can do the same with your bottles of water, just hold them over your stove stove and they will thaw.

  • Interesting thoughts, +1. I don't think most of the techniques you're suggesting would have worked in our situation. Most of the equipment you suggest would have been too heavy and would have had too little capacity. However, I think you're right that the freezer bags would have been superior to the bucket.
    – user2169
    Commented Jan 18, 2016 at 19:48

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