This bill amends provisions related to compensating firefighters, investigators, and police officers for occupational diseases of the lungs caused by heat, smoke, or other noxious gases. The bill introduces conditions for conclusive presumption of disease origin, including retroactive application for filed claims. It outlines examination requirements, employer obligations for examination costs, and benefits for disabled individuals. The bill also addresses claim processing delays, penalties for denied claims, and expenses related to occupational disease claims. The amendments are to apply retroactively to claims filed before the bill's effective date. The bill does not affect local government expenses and becomes effective upon passage.