Wis. Stat. § 891.45: Presumption of employment-connected disease; heart or respiratory impairment or disease.

(1) In this section:

(a) “County fire fighter” means any person employed by a county whose duties primarily include active fire suppression or prevention.

(b) “Municipal fire fighter” includes any person designated as primarily a fire fighter under s. 60.553 (2), 61.66 (2), or 62.13 (2e) (b) and any person under s. 60.553, 61.66, or 62.13 (2e) whose duties as a fire fighter during the 5-year qualifying period took up at least two-thirds of his or her working hours.

(c) “State fire fighter” means any person employed by the state whose duties primarily include active fire suppression or prevention and who is a protective occupation participant, as defined in s. 40.02 (48).

(2) Except as provided in s. 891.453, in any proceeding involving the application by a state, county, or municipal fire fighter or his or her beneficiary for disability or death benefits under s. 40.65 (2) or any pension or retirement system applicable to fire fighters, where at the time of death or filing of application for disability benefits the deceased or disabled fire fighter had served a total of 5 years as a state, county, or municipal fire fighter and a qualifying medical examination given prior to the time of his or her becoming a state, county, or municipal fire fighter showed no evidence of heart or respiratory impairment or disease, and where the disability or death is found to be caused by heart or respiratory impairment or disease, such finding shall be presumptive evidence that such impairment or disease was caused by such employment.