Sometimes "high volume" is simply code for "urban/local metro." In those areas, you'll see job ads that basically advertise that. What they're looking for are people that know how to work fast because their transport times are short and there's going to be another call for them very quickly/soon. When I first started in the field, in a 12 hour day, I'd typically do 8 calls. Considering that each call lasted about 75 minutes on average. I got good at doing calls a bit quicker than that without compromising patient care. When I did my internship with the local fire department, we averaged something like 14 calls/day. Only 2-3 of those were at night. Because our first-in area was so small and we had many hospitals nearby, we could usually be back at the station in about 40-45 minutes. So, yeah, during the daytime, the system out here was (and still is) definitely high volume. The acuity level? Meh. We did see lots of sick patients, but that's because we saw lots of patients...