Which of the following situations requires immediate exit from a contaminated area?

The necessity for immediate exit from a contaminated area is fundamentally based on the safety and health risks associated with radiation exposure. When a dosimeter is alarming, it indicates that the radiation levels are exceeding safe thresholds, which poses an immediate risk to the worker's health. This alarm serves as a critical warning, signaling that the individual's exposure may be approaching or exceeding acceptable limits, thereby necessitating an urgent evacuation from the area to prevent potential radiation sickness or long-term health effects.

In contrast, while wearing protective clothing that is in good condition is important for minimizing exposure, it does not replace the urgent need to leave if radiation levels are dangerously high. Feeling slightly warm may indicate discomfort but does not directly correlate with radiation exposure levels and therefore does not warrant an immediate exit. Identifying a clean area beyond barriers is a proactive step towards safety but again does not trigger the urgency associated with an alarming dosimeter. Hence, the alarming dosimeter is the decisive factor in determining the need for immediate evacuation from a contaminated area.