How each respond is different as well. Another system is a tiered response. This system is becoming more popular in the face of budget cuts and staffing problems but is controversial to EMS field providers. Some police and fire departments work this way. They are in the ambulance while transporting ALS cases because they possibly are the highest level of EMT in many cases.
Fire departments are a logical choice to provide emergency medical care.
They are also the extrication experts and carry the tools. Other types of services. They also provide inter-facility carries from a poorly equipped hospital to a level one trauma center. Fixed wing or plane service can make cross-country trips to deliver a patient to advanced treatments or take someone to a hometown hospital. It ranges from volunteer to salaried supervisors.