How to Build an Igloo BMW iX1 SUV (U11): Model overview, configurator & prices. An illustrated guide to constructing everything from igloos and quinzees to spruce traps and snow trenches. How are the ice blocks of igloos so perfectly formed and fitted, able, it's been said, to withstand the weight of a polar bear? How can you determine if the fresh snow that's fallen outside your front door is as good to make a slab shelter with as a snowman? What is a slab shelter, anyway? For that matter, what are drift caves, spruce traps, snow block walls, and bivy bag shelters, and how would you go about building them, whether for winter fun or protection from the weather? In this instructive, whimsical, illustrated manual, Norbert E. Yankielun, a seasoned cold regions explorer and researcher, takes readers step by step through the process of constructing and inhabiting a range of useful snow structures from the most basic to the more complex. Introductory material on igloo physics, proper winter hydration, fueling tips, and much more, is also included. 100 illustrations.