In patients with or at risk of acute circulatory failure, capillary refill time (CRT) has emerged as a prognostic indicator, with data linking prolonged CRT to mortality and adverse events [1]. Capillary Refill Time (CRT) serves as a reliable and adaptable prognostic marker, with established validation in septic [1], hemorrhagic [2], and cardiogenic shock [3], thereby underscoring its utility across various circulatory failure etiologies. It is now incorporated into diagnostic criteria for acute circulatory failure [4,5]. Unlike laboratory-based hemodynamic markers such as lactate or PCO₂ gap testing, which can be estimated to carry a carbon footprint ranging from several tens to potentially over a hundred grams of CO₂ equivalent per test [6], CRT requires minimal resources and produces virtually no environmental emissions. Normal CRT is typically under three seconds, measured by applying brief pressure to the skin and timing how quickly color returns, thus providing a rapid window into peripheral, and by extension, tissue, perfusion. Hemodynamic coherence—the alignment between macrocirculatory and microcirculatory responses—is often disrupted in circulatory shock. This loss of coherence, observed in septic [7], hemorrhagic [8], and cardiogenic shock [9], underscores the importance of integrating microcirculatory endpoints into resuscitation strategies, as microcirculatory dysfunction may persist despite normalization of systemic hemodynamics.