Ohio Rev. Code § 307.052
The boards of county commissioners of two or more counties may, by adoption of a joint resolution by a majority of the members of each such board, create a joint emergency medical services district for the purpose of providing emergency medical services to the district. The joint resolution shall provide for the financial support of the district by the participating counties, and shall provide for the division of the district's assets among the participating counties in the event the district is dissolved. A district so created shall be composed of all or any portions of the counties as are mutually agreed upon and shall be given a name different from the name of any participating county. No part of a county that is in a joint ambulance district may become part of a joint emergency medical services district without the approval of the board of trustees of the joint ambulance district.
As used in sections 307.052 to 307.058, "emergency medical service" has the same meaning as in section 4765.01 of the Revised Code.
R.C. § 307.052