Cold agglutinins are commonly found in sera of healthy persons. They rarely become clinically apparent due to their activity at lower temperature. In these patients, cardio-vascular operations requiring hypothermia can result in complications like hemolysis, renal failure, myocardial damage and cause unexpected morbidity and even mortality (Agarwal et al., Ann Thorac Surg 60:1143-1150, 1995. Ideally, all patients should be routinely screened pre-operatively for antibodies and management plans made accordingly but the low incidence of the disease, cost of screening tests and the lack of direct relationship between the titers, thermal threshold and risk of complications makes the screening an uncommon practice.