Crab, even you know the answer to this one
You cannot fly below MEA in IMC. Therefore, if you are surrounded by mountains and the MEA is 5000' and the freezing level is 1000' it doesn't take a great deal of working out that the ambulance will be unlikely to do this tasking. That's when SAR is used to carry out transfers and why not.
Now, the icing clearance for the Sea King is pretty awful as well if we are honest and the guys and gals do very few IMC transits in true icing conditions. They don't have to as they have got goggles and can go low level through the hills. Goggles
will come to the AAs, it is just a matter of time.