Idaho Code § 5-331
No action shall lie or be maintained for civil damages in any court of this state against any person or persons, or group of persons, including volunteer ambulance attendants, who offers and administers first aid or emergency medical attention as a part of his volunteer service as an ambulance attendant to any person or persons utilizing the volunteer services and facilities, unless it can be shown that the person or persons offering or administering first aid or emergency medical attention is guilty of gross negligence in the care or treatment offered or administered, or has treated them in a grossly negligent manner. The immunity described herein shall cease upon delivery of the injured or treated person to either a generally recognized hospital for treatment of ill or injured persons, or upon assumption of treatment in the office or facility of any person undertaking to treat said ill or injured person or persons.
Idaho Code § 5-331