What test requires that it be chilled in ice right after collection?

The lactic acid test must be chilled in ice immediately after collection to ensure the accuracy of the results. Lactic acid levels can increase due to ambient temperature and metabolic processes, potentially leading to falsely elevated readings if not properly handled. Chilling the specimen slows down these metabolizing processes, stabilizing the lactic acid levels and providing a more accurate measure of the patient's condition, particularly in cases of suspected lactic acidosis or other metabolic disorders.

In contrast, blood glucose levels can be affected by several factors, but they do not require chilling immediately after collection. A complete blood count (CBC) and thyroid panel also do not necessitate chilling and can be processed under standard temperature conditions, making lactic acid the only test on the list that specifically requires this immediate cooling step for accurate results.