Michigan Compiled Laws, Chapter 3. Federal and Interstate Relations § 3.972

(a) “Emergency responder” means an individual who is required to possess a license, certificate, permit, or other official recognition for his or her expertise in a particular field or area of knowledge and whose assistance is utilized or is desirable during an emergency. Emergency responder includes, but is not limited to, emergency medical services personnel; physicians; nurses; mental health, veterinary, or other public health practitioners; emergency management personnel; public works personnel; and firefighters, including firefighters trained in the areas of hazardous materials, specialized rescue, extrication, water rescue, or other specialized area. Emergency responder does not include law enforcement officers or other law enforcement personnel.

(b) “Mutual aid emergency” or “emergency” means an occurrence or condition resulting in a situation that poses an immediate risk to health, life, property, or the environment, where the governing body having jurisdiction over the situation decides that the situation exceeds its ability to render appropriate aid and that it is in the public's best interest to request mutual aid from a governmental jurisdiction or private entity in another state with which the governing body has a written mutual aid agreement. Mutual aid emergency or emergency does not include a situation that initially raises to the level of disaster or emergency requiring a local or state of declaration of emergency or disaster, unless that declaration occurs after the initial request for mutual aid.