68W is the Army's MOS (Military Occupational Specialty) for Combat Medic. Whisky is the Phonetic Representation of the Letter W.
The 68W is required to complete a 10-week combat training course and advanced individual training sessions for 16 weeks, where they're taught patient care and emergency medical techniques.
CHU is short for Containerized Housing Unit.
Based on Israeli show "TAGAD" (short for Battalion collection station in Hebrew). Original show focuses on a military combat medical unit.