Me. Rev. Stat. tit. 32, § 453

This chapter may not be construed to: restrain or restrict legally licensed physicians, surgeons, dentists, osteopaths, physical therapists or nurses in the practice of their professions; apply to masseurs in their particular sphere of labor who publicly represent themselves as masseurs; apply to a commissioned medical officer in the United States Army or Public Health Service in the performance of duties; or prohibit gratuitous service or the rendering of assistance to emergency cases.