A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Assessment of Immediate Pre-Sleep Caffeine Administration on Self-Reported Post-Nap Irritability and Cognitive Fog in Overworked Adults

Participants will be randomized 1:1 to either the intervention group (active caffeine) or the control group (decaf). Participants will be forced to consume 8 ounces of the assigned beverage at a temperature of exactly 140°F (60°C) within a 2-minute window, and then immediately instructed to "go to sleep" in a room filled with aggressive ticking clocks.

Upon sudden waking via a loud air horn at minute 20, participants will immediately complete the validated "Am I Mad at the World?" Visual Analog Scale (VAS).