While most Klingon warriors are expected to commit Hegh'bat ritual suicide if they become injured, this only applies to those that are dishonored and crippled, while victors and lightly wounded are expected to be treated. Within these colonial sickbays, doctors treat the colonists for plagues by providing vaccines for fellow warriors. Klingon warriors allow them these leisures when the honor of the Empire is at stake.
The medical officer of the colony also resides at this location. Several upgrades improve the capability of the sickbay and can even increase the population of the colony. (TOS video game: New Worlds)