40 ILCS 5/6-140
Unless the performance of an act or acts of duty results directly in the death of the fireman, or prevents him from subsequently resuming active service in the fire department, the annuity herein provided shall not be paid; nor shall such annuities be paid unless the widow was the wife of the fireman at the time of the act or acts of duty which resulted in his death.
For the purposes of this Section only, the death of any fireman as a result of the exposure to and contraction of COVID-19, as evidenced by either (i) a confirmed positive laboratory test for COVID-19 or COVID-19 antibodies or (ii) a confirmed diagnosis of COVID-19 from a licensed medical professional, shall be rebuttably presumed to have been contracted while in the performance of an act or acts of duty and the fireman shall be rebuttably presumed to have been fatally injured while in active service. The presumption shall apply to any fireman who was exposed to and contracted COVID-19 on or after March 9, 2020 and on or before January 31, 2022 (including the period between December 31, 2020 and the effective date of this amendatory Act of the 101st General Assembly); except that the presumption shall not apply if the fireman was on a leave of absence from his or her employment or otherwise not required to report for duty for a period of 14 or more consecutive days immediately prior to the date of contraction of COVID-19. For the purposes of determining when a fireman contracted COVID-19 under this paragraph, the date of contraction is either the date that the fireman was diagnosed with COVID-19 or was unable to work due to symptoms that were later diagnosed as COVID-19, whichever occurred first.
40 ILCS 5/6-140