Heat-proof vessels are given to the player by Petrified Pete upon entering the Volcanic Mine. This vessel has 35 uses per game (70 when upgraded), in which water can be thrown to harden the lava, allowing players to walk on them. However, the lava hardened by the vessel will melt after 90 seconds, giving players limited time to stand on them. If players remain on the hardened lava when it melts, they will fall into the lava, taking massive damage.
The water can only be thrown while the player is facing north, east, south, and west. Additionally, the water canteen can be right clicked to open a dialogue box to throw water in a certain direction without moving your character, or right clicking while it is equipped to select the direction the player wants to throw it at.
With 10,000 points from the Volcanic Mine, Petrified Pete can upgrade their vessel to hold more charges, increasing it from 35 to 70.