In the face of certain death, burning a fate point will ensure the survival of your character.
When a character burns fate to resist damage which would guarantee their death (ie: 10 on a critical injury), the critical effects are ignored and the PC falls to the ground with 0 wounds. At this point they are out of the fight for that encounter, and will be ready for combat for the next encounter assuming medical attention can be provided. Burning Fate will take the PC out of the fight completely, and provides a 100% guarantee of survival.
Critical Injuries that result in the loss of a limb will have that limb replaced with a Cybernetic of Standard Quality as soon as the PC can reach a field hospital or supply depot.
Wounds which may kill a character outright may instead destroy their equipment, depending on GM discretion.