A Heart Canister is an item that permanently increases your maximum health by one heart (2 health) per canister equipped, up to a maximum of 20 hearts (40 health). They are used by either right clicking with them, or by placing them in the appropriate slot in the 'o' menu. The extra hearts are shown as orange and cover up the standard red health, rather than be shown above them. They are useful for exploring and battling monsters.
- A player can remove their heart canisters so that they have more health than their maximum until they take damage. For example, if you have one heart canister and 11/11 hearts, and you take it out of your 'o' menu slot, you will have 11/10 hearts. Your health will therefore not regenerate until you reach 9.5 or fewer hearts. Healing in any way when under effect of this 'bug' will set the health to the current maximum.
- You will not drop them on death. However, you will respawn with 10 hearts of health regardless, but your extra health will still regenerate from natural health regeneration.