The board shall require all firefighters receiving disability pensions to be examined every six months. All such examinations shall be made by physicians duly appointed by the board. If a firefighter shall fail to submit to such examination within ten days of having been so ordered in writing by said retirement board all pensions or benefits paid to said firefighter under this chapter, shall immediately cease and the disbursing officer in charge of such payments shall issue no further payments to such firefighter. If such firefighter fails to present himself or herself for examination within thirty days after being ordered so to do, he or she shall forfeit all rights under this chapter. If such firefighter, upon examination as aforesaid, shall be found fit for service, he or she shall be restored to duty in the same rank held at the time of his or her retirement, or if unable to perform the duties of said rank, then, at his or her request, in such other rank, the duties of which he or she is then able to perform. The board shall thereupon so notify the firefighter and shall require him or her to resume his or her duties as a member of the fire department. If, upon being so notified, such member shall fail to report for employment within ten days, he or she shall forfeit all rights to any benefits under this chapter.