Changes in the Emergency Medical Service reducing the provision for air raid casualties. General. Strictly speaking, the term "Emergency Medical Service" means body of doctors enrolled and paid by the Department for service under the mergency hospital arrangements. It is commonly used also to denote the mergency hospital arrangements themselves, more accurately known as the mergency Hospital Scheme. In either case it must be remembered that these rrangements do not constitute a separate service in any way comparable with the ###rmy Medical Service.