Fun fact, this is largely a consequence of the reduction in house fires since building codes were improved in the mid to late 20th century. As house fires got r

Fun fact, this is largely a consequence of the reduction in house fires since building codes were improved in the mid to late 20th century. As house fires got rarer, cities had a conundrum; you obviously still need firefighters when fires cropped up, but the reduced rate of them made them sit idle a lot. The shift of medical duties into firefighters was a solution to that problem; give them something productive to do between increasingly rare house fires.