Frost heave is a geological phenomenon that occurs when soil expands and contracts due to freezing and thawing cycles. When water in the soil freezes, it turns into ice, which takes up more space than liquid water. This expansion can push the ground upward, causing uneven surfaces and damage to structures like roads and foundations. The process is most common in areas with cold climates, where temperatures frequently fluctuate around the freezing point. Proper drainage and insulation can help mitigate the effects of frost heave, protecting infrastructure and maintaining the stability of the ground during winter months.