Describes the effects of cold climates on the surface of the earth. Using scientific principles, the authors describe the evolution of ground thermal conditions and the origin of natural features such as frost heave, solifluction, slope instabilities, patterned ground, pingoes and ice wedges. The thermodynamic conditions accompanying the freezing of water in porous materials are examined, and their fundamental role in ice segregation and frost heave processes is demonstrated in a simple manner.