A brief update adding to the Injury Rules on page 7

While a Health Value is at zero you cannot Push a roll using either of that Value’s two Abilities but you must re-roll any 1s as if you had. 

Each time a Value reaches zero roll on the Injury Severity Table. If a Value already has an injury, still roll on the Table only gaining a new injury for that Value only if the Severity is worse than a previous one.

You only suffer the negative effect to your rolls from your most severe injury. If you have two Minor Injuries and one Serious Injury, you only add the 2 Banes from the Serious Injury.

If you take damage while all of your Values are at zero, roll on the Injury Severity Table and gain an additional injury.

This is to help prevent the Death Spiral and reduce the number of Banes rolled when getting close to death as well as to help not punish players for healing when a health value is at zero and then damage immediately taking them back to zero. Of course... if you wanted things to be especially dire as a GM you could remove this limit and have players roll with as many Banes as they have injuries.