Which method is NOT effective for thawing frozen food safely?

Thawing frozen food safely is crucial to prevent the growth of harmful bacteria. Thawing at room temperature is not an effective method because food can remain in the "danger zone" (between 40°F and 140°F), where bacteria multiply rapidly. When food is left out on the counter, it can thaw unevenly, leading to some portions reaching temperatures that allow bacteria to thrive, while other parts may still be frozen.

In contrast, thawing in the refrigerator is safe because it maintains a consistent, cold temperature, allowing the food to thaw gradually without entering the danger zone. Thawing under cold running water is also effective, as the continuous flow keeps the food at a safe temperature. Using a microwave is acceptable as long as the food is cooked immediately after thawing to avoid any bacterial growth. Therefore, thawing at room temperature is the method that poses the highest risk for foodborne illness.