This chapter shall not apply to the performance of the duties of any commissioned or contract physical therapist or physical therapist assistant while practicing in the United States Armed Services, United States Public Health Service or United States Department of Veterans Affairs as based on requirements under federal regulations for state licensure of health care providers, or to a physical therapist or a physical therapist assistant licensed or certified and in good standing with the applicable regulatory agency in the state, District of Columbia, or Canada where the practitioner resides when the practitioner is in Virginia temporarily to practice for no longer than sixty days (i) in a summer camp or in conjunction with patients who are participating in recreational activities, (ii) in continuing education programs, or (iii) by rendering at any site any health care services within the limits of his license or certificate, voluntarily and without compensation, to any patient of any clinic which is organized in whole or in part for the delivery of health care services without charge as provided in § 54.1-106.