"do you know why" or "have an idea why" might be a good jumping off point, though a lot slower to say. "Are you aware of any existing conditions (that might be relevant to this emergency)" is probably too long.
"Do you know why" sounds pretty good. It's not only less demanding, it's less likely to attract a guess from someone who feels obliged to answer.
Emergency Medical Dispatch is a fascinating case study of technical communication in general. Lots of jobs train people to communicate urgent information clearly, but EMD has exceptionally specific limitations. Only one side of the call is trained, so you can't rely on rehearsed protocols like EMTs or police officers would. And the priority of information is completely unintuitive to most of us because it's not just importance, but sequencing: info needed to dispatch an ambulance comes first, then info to help the caller do first aid, and only after that the seemingly crucial stuff like "what's actually making them sick".
