Obtaining water from ice and snow
When Samuel Taylor Coleridge wrote “Water, water everywhere, nor any drop to drink”, he was describing sailors dying of thirst at sea. Two centuries later, that same irony still plays out — not on the ocean, but in glacial and polar environments where water is everywhere, yet completely locked away in ice and snow.
In cold, high-altitude landscapes, dehydration can become a serious threat surprisingly quickly. Knowing how to safely convert snow and ice into drinkable water isn’t just useful — it’s essential for anyone travelling above the snow line.
To do it properly, it helps to understand the science behind water itself.
The Basics: How Water Behaves
Water exists in three states depending on temperature (and slightly on altitude):
Below 0°C: frozen as ice or snow
Between 0°C and 100°C: liquid water
Above 100°C: vapour (steam)
In cold environments, your challenge is simple in theory but demanding in practice: convert frozen water into liquid efficiently, safely, and without wasting precious fuel.
Melting Snow with Modern Equipment
Most mountaineers and winter explorers today carry compact stoves running on white gas, unleaded petrol, propane, or modern multi-fuel systems. These are reliable tools — but how you use them matters.
Never fill a pan with snow from the start. Snow is mostly air and acts as an insulator. Packing a pan full can cause the base to overheat and even burn through before the snow melts.
Instead:
Start with a small amount of clean snow (definitely not yellow).
Heat gently until it melts into water.
Gradually add more snow in small handfuls.
Cover the pan to conserve fuel.
You’ll quickly discover how much snow it takes to make a single litre of water — far more than most people expect.
If you have access to wood, the same method works over an open fire.
Is Melted Snow Safe to Drink?
Freshly fallen snow is often safe to drink once melted — but never assume frozen water is sterile. Freezing does not kill bacteria or microorganisms; it simply puts them into dormancy.
Treat melted snow or ice the same way you would any natural water source:
If in doubt, boil for at least 10 minutes
Or use modern purification methods (filters or tablets)
Melting Without a Pot
If you don’t have a heatproof container, all is not lost.
Soft snow can be wrapped in a T-shirt or other porous fabric and suspended over a fire, allowing water to drip into a container.
Hard crust snow or solid ice can be broken into a ring or “doughnut” shape, skewered on a stick, and rotated slowly over heat to melt evenly.
These methods are slower but effective in emergency situations.
Finding Water Without Fuel
Even in sub-zero temperatures, the sun can work in your favour.
Dark rocks absorb radiant heat and often create small meltwater flows where snow or ice touches stone — even when air temperatures remain well below freezing. I’ve found flowing water this way at –10°C.
Tips:
Listen for the sound of running water
Focus on south-facing slopes and cliff faces
Channel meltwater into containers when you find it
This water source usually disappears after sunset, so hydrate and collect as much as possible during daylight.
At night, keep water bottles inside your sleeping bag to stop them freezing. A favourite trick is filling a water bag with hot water and using it as a heat source — practical and luxurious.
Why Eating Snow Is a Bad Idea
Sucking snow or ice should be a last resort only.
It lowers your core body temperature, increases the risk of hypothermia, and can even cause cold burns to your lips and mouth. You’ll lose more heat than you gain hydration.
Preparation Makes the Difference
Cold environments are unforgiving. Success — and safety — depend on preparation, sound judgement, and the right equipment.
Before venturing into glacial or polar terrain:
Seek advice from qualified mountain leaders or experienced winter explorers
Invest in reputable equipment from trusted outdoor suppliers
Learn skills before you need them
While glaciers are among the most challenging environments on Earth, they also offer unparalleled beauty and profound personal reward.
Reading about survival skills builds knowledge — but nothing replaces hands-on experience with a professional instructor. If you’re serious about learning these techniques properly, training in the field is invaluable.