fastigium

noun

1. An apex or summit; culmination.
2. A pediment or gable end.
3. The most intense phase of a disease, especially a fever.

   “[W]e find that the duration and succession of the febrile phenomena constitute five principal groups. […] 2. Fevers which are essentially continuous in their course (continued fevers), which exhibit but slight daily differences of temperature during their fastigium or acme, and defervesce rapidly (by crisis).”