Final answer:
In PS Trax, we check the 'Tired Thread' to monitor the performance of a computer program or system.
Step-by-step explanation:
In the context of PS Trax, we check the 'Tired Thread' when it's necessary to monitor the performance and efficiency of a computer program or system. 'Tired Thread' could refer to a particular thread in a multi-threaded program that appears to be running slower or using more resources than expected. By identifying and troubleshooting the tired thread, we can ensure optimal performance of the program or system.