Lava is the viscous liquid that erupts through a volcano from below the earth's surface. Initially, when it comes out, the cooling process starts almost immediately forming a thin crust layer however, it is not to be deceived by the looks of it as it is not cool enough for humans to go near or touch it by any chance. Due to the insulating properties that lava consists of, it takes several years for it to completely subside its heat and flowing properties. It also depends on the temperature of the surrounding where the lava erupts as the climate plays a vital role in the cooling down of the lava into rock form.