A sign that a firefighter needs to spend more time in the rehab area would be:

A pulse rate in excess of 120 beats per minute is a significant indicator that a firefighter may be in need of more time in the rehabilitation area. Elevated heart rates, especially beyond this threshold, suggest that the firefighter could be experiencing cardiovascular stress or fatigue, which can be a critical concern in the high-stress environment of firefighting. Staying in the rehab area allows for proper monitoring of vital signs, hydration, and recovery, ensuring that the firefighter is fit to return to duty or identifying if further medical evaluation is necessary.

Other factors, though potentially relevant, do not provide as direct a signal about the need for extra recovery time. For instance, an unfinished water allotment may indicate a need for hydration but does not inherently signify immediate distress. Diastolic blood pressure readings under 90 mm Hg can indicate hypotension, but context is essential, and a trained professional would evaluate this alongside other signs. Similarly, if a firefighter hasn't finished eating, it might suggest they're still recovering, but it does not primarily indicate an urgent need for additional rehab time. Thus, the heightened pulse rate is a more critical and immediate indicator of the need for further attention in the rehab area.