What should be the first priority for a casualty after decontamination in the cold zone?

After decontamination in the cold zone, the first priority for a casualty should be a thorough re-triage and assessment. This step is crucial because it allows medical personnel to evaluate the casualty's condition accurately after the initial decontamination process. Re-triage ensures that any potential injuries or medical needs that were not initially identified can be addressed, as the casualty may be experiencing symptoms that could worsen without proper assessment.

The re-triage process helps in prioritizing treatment based on the current state of the casualty, which may have changed due to exposure or decontamination procedures. It ensures that the most urgent medical needs are identified and managed appropriately, thereby improving the chances of a favorable outcome.

The other options, while important, come after a thorough assessment: ensuring proper evacuation is vital, but it should not occur until the patient's condition has been clarified; psychological support is essential for trauma management but should follow medical assessments; secondary decontamination may be necessary in some cases but must only occur after re-evaluating the casualty's health status.