Freezing means that something turns from a liquid state to a solid state. The molecules go from moving around as a liquid to a stationary solid crystal structure. The molecules of oils, fats, and waxes, unlike water molecules, are too long to form very good crystals, so they usually turn into amorphous lumps, like a lump of butter, or ear wax, when they are cooled. A good example of this is butter. Butter is a solid at normal room temperature, becomes harder when cooled, and will melt into a liquid when heated. Likewise, pure olive oil is a liquid at room temperature but turns solid when put it in the fridge. All oils would get pretty sticky, if not actually solid, at 270 degrees below zero.