Minecraft wiki entry for Mining, associated text: Horizontal mining is not as dangerous as vertical. But there are some similar suggestions. Carry a water bucket and some blocks of some disposable, non flammable material (e.g. sand, gravel, cobblestone) somewhere on the player's hotbar. A block can be used to quickly plug the leakage in cases of lava, and water can be poured over source lava to turn it into obsidian, as well as to put out fires. (Flowing lava will usually turn to cobblestone, occasionally stone, if the water is a source block.)