Plak tow

From Memory Alpha, the free Star Trek reference

Plak tow is a Vulcan phrase literally meaning "blood fever." It is the final stage of pon farr, characterized by a combative nature and a high fever. Normally a Vulcan in this state will be unable to speak or think clearly. T'Pau was therefore surprised when Spock, while suffering from pon farr, protested T'Pring's choice of Kirk as her champion in the koon-ut-kal-if-fee. (TOS: "Amok Time")

The "fever" is broken through the koon-ut-kal-if-fee, either through the successful completion of a marriage, or through combat. (VOY: "Blood Fever")