I don't like the idea of locking threads just because a certain amount of time has passed. Many cases presented in that section have no clear cut solutions and take weeks or even months to resolve. It is really nice to be able to hear follow-up stories well after the fact, too. Locking these threads up would prevent the OP from submitting those follow-ups.
I will admit that the Emergencies section is large and turns over rapidly, but I don't see any solution to that unless people stop having emergencies. There are lots of folks over there that do their best to answer most questions that come through. Rarely, a question will get missed, but that is usually more that no one has an answer for the question rather than the question got missed.