Relearn how to use and maintain your vessel.
Run it at 37°C. Every ice-cold drink forces the engine to spend precious heat just to bring that water up to body temperature. Cold constricts vessels — physics, not culture.
Marketing told you how to live; your body remembered. Stage III is the theory check before Stage IV hands-on practice — the written test before the road test.
Below 36°C metabolism slows and immunity drops. Above 37°C it is an emergency response. The 37°C red line is non-negotiable for every biological robot.