The first step in building a snow shelter is to put weight on the snow. This causes friction, which causes snow molecules to bond together. An easy way to do this is to walk back and forth on the snow.
The next step is to cut blocks from the compacted snow. The blocks will eventually become your roof.
This snow shelter will require twelve blocks of snow, six on a side. “The whole idea,” says Madonna Lengerich of Idaho Mountain Search & Rescue, “is don’t break the block!
"Let them come together. As you can see, they are offset, so now I can set the blocks in one by one, by myself. I bevel them and set them against the other edge. And they pretty much stay, right where you put them!"
The next step is to throw a bunch of snow on top.
“The fun thing about snow is if you hold it for awhile, it will solidify and it will stay. Within a few minutes, you’ll be able to walk on top of this!”
“If you figure that it’s –10(F) outside and 30 degrees Fahrenheit inside, that’s a 40 degree temperature differential,” says Mark Casson of Idaho Mountain Search & Rescue. “That’s the difference between freezing your feet and basically having no problem whatsoever.”