You're not going to get rich doing it.
Some jobs employ enough pilots to do 12 or 14 our shifts, but many still do around the clock on call (a violation of the regulation, but far from extinct).
I've flown for four different aeromedical operations over the years, everything from remote dirt airstrips to international turbojet operations, piston, turboprop, turbojet, administrative flying, organ recovery, and emergency medical.
At a lot of operations, more stock is placed in the wishes of the medical personnel than that of the pilots. I didn't tolerate that; never let medical personnel influence safety of flight decisions. That becomes a real problem if the company is run or operated by medical personnel.
There are some ok operators out there, and a lot that aren't.
There are a number of operators who illegally discriminate over insurance. It's common for a hospital or clinic to call for a transport, and be asked for the patient's insurance information. When its insufficient or the patient is uninsured, the medical facility is told that the airplane just broke down, or is assigned to another flight. This isn't legal, but it happens a lot. I refused to work for operators that do that.
Air ambulance flying generally doesn't have a lot of pilots who stay with it long term.