(a) The term "employer," as used in this section, shall mean and include an individual, a partnership, an association, a corporation, a legal representative, a trustee, receiver, trustee in bankruptcy, and any common carrier by rail, motor, water, air or express company doing business in or operating within the state.
(b) The term "employee" shall mean and include every person who may be permitted, required or directed by any employer, as defined in subsection (a), in consideration of direct or indirect gain or profit, to engage in any employment.
(c) It shall be unlawful for any employer, as defined in subsection (a) to require any employee or applicant for employment to pay the cost of a medical examination as a condition of employment.
(d) Any employer who violates the provisions of this section shall be liable to a penalty of not more than $100 for each and every violation. It shall be the duty of the commissioner of labor to enforce this section.