I dont' think that 52 is a problem, but like other said, they tend to hire you. Is your back (and belly) up to long hours, horrible elements, being crouched under (or in) a car trying to intubate, carrying a backboard 100 yards to the helo, manuevering in the cramped on-board conditions?

Are you thinking like 911, medivac work, or the long-distance transports?

If you're really having a tough time locally, I know lots of areas that are remote will have air ambulances, and those folks tend to be bit older. Places like Alaska, I'd assume Canada, etc. Of course, you'd better enjoy moving there!