One recommendation I got in case of emergency or intentional sheltering in a snowy location is to dig a lower hole, so that the cold air can move there, while one can sleep higher up where the heat stays. I understand the physics involved, but I am not aware of how much difference it can do in practice. How many degrees are we talking here ? Is it really recommended, or does it just waste energy ?

  • 1
    This also referred to as a "cold air sump".
    – furtive
    May 11, 2012 at 2:40
  • We dug a snow cave in scouts when I was 13. It was Rexburg, Idaho, middle of the winter, so we are looking down around -25f (-30c) outside with the windchill way frekn lower. We used the step up but I thought it was for the water drainage. Anyway, it was warm enough to sweat in the cave. Never did a cave without one to compare, but physics cause me to think it is a good idea.
    – BillyNair
    Jul 17, 2012 at 0:22

1 Answer 1


Doing it correctly can ensure the temperature of the snow cave maintains around 32°F (0°C) or higher.

Its not just about digging the extra hole but how the entire cave is constructed that can make the difference between life and death.

Here's the general idea.

enter image description here

Of course doing this won't guarantee your safety, but it sure helps.

To answer your question directly, it makes a huge difference and is absolutely recommended.

EDIT As pointed out in the comments, we should always give credit to those from whom we get information from.

Source: Mike Clelland

  • Good use of a Mike Clelland drawing :)
    – Ryley
    Jan 26, 2012 at 0:05
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    Can we credit the authors on this use of their work please! It's a great book and I think many people would like to read it... Allen and Mike's Really Cool Backcountry Ski Book They are two NOLS instructors who have done a great job getting information out there to the masses. Bios - (linkedin.com/in/alleno), (littleboingmarks.blogspot.com) Jan 26, 2012 at 21:56
  • You are right, I should have. I pulled it from google images without looking for where it came from. Jan 26, 2012 at 22:40
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    32 degrees???? That would melt all immediatelly... Aaaah, you must mean 32 degrees Fahrenheit, not Celsius! Right?
    – Tomas
    Jan 28, 2012 at 0:58
  • I have recently created a Wikipedia article on this topic: Cold hole. We're talking 2016, so either people just don't know about this practice (and I mean Wikipedia, duh!) – or I'm using my words wrong, and the article already exists under a different title. I'm no hiking enthusiast (let alone mountaineer or climber), but I love the physics rationale – so I need help here from someone with an actual drive to set things right. Long story short: help! :) Jan 22, 2016 at 0:17

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