Air Zermatt in Switzerland is one of the busiest professional mountain rescue/HEMS-operations in the world.
During peak season the activity is intense with helicopters landing or taking off all the time. Watching the ground crews working with refuelling, making adjustments, loading and unloading is like watching a formula 1 pit crew. I recommend anyone with an interest in mountain rescue to visit their base in Zermatt. They have developed their own brand of specialised HEMS and pull off some spectacular rescues. They also do courses and training in mountain medicine through their Alpine Rescue Center.