This article describes a study that aimed to: (1) identify risk factors for in-hospital cardiac arrest; (2) formulate activation criteria to alert a clinical response culminating in attendance by a Medical Emergency Team (MET); and (3) evaluate the sensitivity and specificity of the scoring system. A multivariate analysis of cardiac arrest cases identified three positive associations: abnormal breathing, abnormal pulse, and abnormal systolic blood pressure. Risk factors were weighted and tabulated, and formulated into a table of activation criteria for alerting a clinical response.