Sorry, but I won't be plugging any unknown usb drives into the ambulance's computer,
That's a Windows problem, not a USB issue.
The real problem is what kind of file is there, and what kind of reader is needed. I've billed many hours to clients who call and say "I was sent a FOO.XYZ file, how do I read it?". I've had to take apart files and extract data by hacking it out ($$$).
Even if Windows is banned from ER and ambulances to fix the security/virus problem, there's no way to expect anyone to know what to do with any material other than printed English text.