How to Heal in Kos

Each wound has a base 25% chance of becoming infected.  If left untreated, this chance increases by 5% each day for 3 days, or until healed.  Wounds taken in filthy conditions or inflicted by unsanitary weapons may have much higher rates of infection.
Wounds heal at a rate of 1 hit point a day.

Dutch Courage: A quick swig of liquor will recover 1d4 hit points.  These hit points will disappear after 1 hour.  This only works once per wound.

Cauterize: Heating a metal object and applying it to a wound will cause 1d4 hit points of damage, but will prevent the wound from becoming infected.

Sew: Sewing wounds allows them to heal at a rate of +1 hit points per day.  A character must have 12+ Skill to sew wounds, as well as a needle and thread.  A character must have 14+ Skill to sew his own wounds.

Bandage: Bandaging wounds with clean bandages allows them to heal at +1 hit points per day.  Dirty bandages provide the same effect, but increase the chance of infection by 10%.

Good conditions: Recuperating in luxury increases the rate of healing by +1 hit points per day.  This means clean, warm blankets, eating hot and copious meals three times a day, and enjoying maximum bed rest.

Washing the wound: Washing the wound decreases the chance of infection by 5%.  Washing it in alcohol, holy water or another sterile substance decreases the chance of infection by 10%.

Leeches: The application of leeches or other blood-suckers can repair damage from infection or poison, at a rate of +1 points healed per day.

Some herbs may allow the wound to heal much faster.  Only a seasoned woodsman, botanist or physician knows what herbs these are or where to find them.

INFECTION
When a wound becomes infected, it no longer heals.  Each day, the subject must roll under his fortitude, or the infection grows worse.
Level 1: Deals 1 damage.
Level 2: 1 damage, fevers; -1 to all stats
Level 3: Limb must be amputated.  If it is in a critical location (ie torso, neck, head), the wound continues to do damage at a rate of 1 damage and -1 to all stats until either it heals or kills the character.
If the character successfully rolls under his Fortitude 3 times, he has fought off the infection and suffers no further effects.  Any debilitation from the infection will heal at the normal rate.  Changing the bandages or re-dressing the wounds allows the character to re-roll his daily Fortitude test if it is a failure.