A recent experience of a racer mate of mine who did a trackday at Cadders....
Long story short, the organisers let a man with a known broken Femur get himself to hospital for treatment as they had only one ambulance at the event and had to keep it "for emergencies".
This is the biggest fookin bone in your body and a fracture can have all manner of horrendous complications, including potentially lethal clotting.
This is a well known outfit, and they are NOT the only ones to do this.
Please check the emergency cover at any event you are considering.
It's no bleedin wonder I do all my events abroad these days.