Every five days, wounded or Incapacitated characters may make Vigor rolls. Wild Cards remove one wound level (or their Incapacitated status) with a success, or improve two steps with a raise. A critical failure on a natural healing roll increases a Wild Card's wound level by one. If the hero already has three wounds he becomes Incapacitated. Extras lose their Incapacitated status with a success and expire if they roll a 1 on their Vigor die.
Subtract wound penalties from these rolls as usual, as well as any of the modifiers below. These are cumulative, so rough traveling in intense cold with one wound is a total penalty of -5, for example.
Medical attention means that someone with the Healing skill is actively checking the patient's wounds, changing dressings, giving what medicines are available, and generally looking after the patient's well-being.
Savage Worlds Deluxe Edition p. 88