Final answer:
The priority rationale for frequent linen changes is to prevent the spread of infection and control odor.
Step-by-step explanation:
The priority rationale for frequent linen changes in a patient who is on long-term bed rest and requires frequent linen changes due to excess diaphoresis is to prevent the spread of infection and control odor.
Excess diaphoresis, or sweating, can lead to dampness on the linen, which creates a breeding ground for bacteria. Regular linen changes help maintain hygiene, prevent the growth of bacteria, and minimize the risk of infection. Additionally, frequent linen changes help control odor, as sweat can become trapped in the fabric and cause unpleasant smells.