Every two weeks, each uninfected wound that a character has will get better by one level (e.g. a Scratch heals completely, a Light wound becomes a scratch, a Critical wound becomes Serious).
Successful use of Medicine speeds up this healing rate. A medic can increase the healing rate by making a dice roll using his/her PE + Medicine (including Healing wounds specialism). For every 2 points of dice roll result, the time required before the wound gets better by one level is reduced by one day.
The rapid healing and regenerates talents halve the time that is required before the wound gets better.
See also: example of a wound.