Notwithstanding any other provision of Sections 6-151, 6-151.1, and 6-154, an active fireman who is certified to be terminally ill by a Board-appointed physician may, upon such certification, make application with the Board for a determination that the participant is eligible to receive a disability benefit, even though, at the time, the participant has the right to receive salary. However, an active fireman may not receive any such disability benefit payments at the same time the participant receives salary.