How to Make an igloo

	Step 1. Cut blocks from dry, hard, hard snow, using a snow saw or large knife. Each block should be about 3 ft. (1m) long, 15 in. (40cm) high, and 8 in. (20cm) deep.
	Step 2. Form a circle with blocks around the hole created where you cut the blocks. Cut the circle in a spiral from the top of the last block to the ground ahead of the first block. This will make it easy to construct a dome.
.	Step 3. Build up walls, overlapping the blocks and shaping them so that they lean inward. Cut a hole under the wall for the cold sink and entrance. Put several blocks along one wall as a sleeping platform
.	Step 4. The last block must initially be larger than the hole. Place the block on top of the igloo, then, from inside, shape and wiggle it to slot exactly into the hole
	Step 5. Hot air from your body and stove rises and is trapped inside the dome. Cold air falls into the sink and flows away to the outside. It is essential to cut ventilation holes in the walls with an ice axe.
	Finished IglooWith warmth inside the igloo, the surface of the walls will melt and freeze over, to form a smooth, airtight ice surface. The roof over entrance tunnel prevents snow from blowing into igloo.