In what situation should a blood specimen be warmed before collection?

Warming a blood specimen is particularly important for specific coagulation tests that require warmed blood because certain tests, such as those assessing the function of coagulation factors, can be affected by temperature. When blood is drawn at a lower temperature, it may lead to inaccurately high results, as some coagulation factors perform differently under cooler conditions. This is especially crucial in tests involving platelet function, where low temperatures can suppress platelet activity and lead to misleading results.

By warming the specimen before collection, the phlebotomist ensures that the blood components are in their optimal state for analysis, thus providing more accurate and reliable test results. The practice of warming blood specimens is not typically required for routine specimens or all blood draws, nor is it exclusively tied to hospitalized patients, making this situation specific to coagulation testing procedures.